[PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[K. Y. Srinivasan]

The storage driver (storvsc_drv.c) handles all block storage devices
assigned to Linux guests hosted on Hyper-V. This driver has been in the
staging tree for a while and this patch moves it out of the staging area.

This patch is based on the storvsc patches that are already on Greg's queue
for the staging tree. This patch-set addressed Christoph's review comments.
If need be, I can re-send this patch-set in Greg's queue
or I can  send the fully patched storvsc_drv.c.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/scsi/Kconfig                       |    7 +++++++
 drivers/scsi/Makefile                      |    3 +++
 drivers/{staging/hv => scsi}/storvsc_drv.c |    0
 3 files changed, 10 insertions(+), 0 deletions(-)
 rename drivers/{staging/hv => scsi}/storvsc_drv.c (100%)

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 16570aa..d3d18e8 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -662,6 +662,13 @@ config VMWARE_PVSCSI
 	  To compile this driver as a module, choose M here: the
 	  module will be called vmw_pvscsi.
 
+config HYPERV_STORAGE
+	tristate "Microsoft Hyper-V virtual storage driver"
+	depends on SCSI && HYPERV
+	default HYPERV
+	help
+	  Select this option to enable the Hyper-V virtual storage driver.
+
 config LIBFC
 	tristate "LibFC module"
 	select SCSI_FC_ATTRS
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 2b88749..e4c1a69 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -142,6 +142,7 @@ obj-$(CONFIG_SCSI_BNX2_ISCSI)	+= libiscsi.o bnx2i/
 obj-$(CONFIG_BE2ISCSI)		+= libiscsi.o be2iscsi/
 obj-$(CONFIG_SCSI_PMCRAID)	+= pmcraid.o
 obj-$(CONFIG_VMWARE_PVSCSI)	+= vmw_pvscsi.o
+obj-$(CONFIG_HYPERV_STORAGE)	+= hv_storvsc.o
 
 obj-$(CONFIG_ARM)		+= arm/
 
@@ -170,6 +171,8 @@ scsi_mod-$(CONFIG_SCSI_PROC_FS)	+= scsi_proc.o
 scsi_mod-y			+= scsi_trace.o
 scsi_mod-$(CONFIG_PM)		+= scsi_pm.o
 
+hv_storvsc-y			:= storvsc_drv.o
+
 scsi_tgt-y			+= scsi_tgt_lib.o scsi_tgt_if.o
 
 sd_mod-objs	:= sd.o
diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
similarity index 100%
rename from drivers/staging/hv/storvsc_drv.c
rename to drivers/scsi/storvsc_drv.c
-- 
1.7.4.1

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[James Bottomley]

On Wed, 2012-01-25 at 10:29 -0800, K. Y. Srinivasan wrote:
> The storage driver (storvsc_drv.c) handles all block storage devices
> assigned to Linux guests hosted on Hyper-V. This driver has been in the
> staging tree for a while and this patch moves it out of the staging area.
> 
> This patch is based on the storvsc patches that are already on Greg's queue
> for the staging tree. This patch-set addressed Christoph's review comments.
> If need be, I can re-send this patch-set in Greg's queue
> or I can  send the fully patched storvsc_drv.c.
> 
> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> ---
>  drivers/scsi/Kconfig                       |    7 +++++++
>  drivers/scsi/Makefile                      |    3 +++
>  drivers/{staging/hv => scsi}/storvsc_drv.c |    0
>  3 files changed, 10 insertions(+), 0 deletions(-)
>  rename drivers/{staging/hv => scsi}/storvsc_drv.c (100%)

This doesn't compile:

make[3]: *** No rule to make target `drivers/staging/hv/storvsc_drv.o',
needed by `drivers/staging/hv/hv_storvsc.o'.  Stop.
make[3]: *** Waiting for unfinished jobs....
  LD      drivers/staging/hv/built-in.o
make[2]: *** [drivers/staging/hv] Error 2
make[1]: *** [drivers/staging] Error 2
make[1]: *** Waiting for unfinished jobs....
make: *** [drivers] Error 2

You need to remove the staging Kconfig/Makefile remnants as well.

James

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[Rolf Eike Beer]

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Am Mittwoch 25 Januar 2012, 10:29:47 schrieb K. Y. Srinivasan:
> The storage driver (storvsc_drv.c) handles all block storage devices
> assigned to Linux guests hosted on Hyper-V. This driver has been in the
> staging tree for a while and this patch moves it out of the staging area.
> 
> This patch is based on the storvsc patches that are already on Greg's queue
> for the staging tree. This patch-set addressed Christoph's review comments.
> If need be, I can re-send this patch-set in Greg's queue
> or I can  send the fully patched storvsc_drv.c.
> 
> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> ---
>  drivers/scsi/Kconfig                       |    7 +++++++
>  drivers/scsi/Makefile                      |    3 +++
>  drivers/{staging/hv => scsi}/storvsc_drv.c |    0
>  3 files changed, 10 insertions(+), 0 deletions(-)
>  rename drivers/{staging/hv => scsi}/storvsc_drv.c (100%)
> 
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index 16570aa..d3d18e8 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -662,6 +662,13 @@ config VMWARE_PVSCSI
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called vmw_pvscsi.
> 
> +config HYPERV_STORAGE
> +	tristate "Microsoft Hyper-V virtual storage driver"
> +	depends on SCSI && HYPERV
> +	default HYPERV
> +	help
> +	  Select this option to enable the Hyper-V virtual storage driver.
> +
>  config LIBFC
>  	tristate "LibFC module"
>  	select SCSI_FC_ATTRS
> diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
> index 2b88749..e4c1a69 100644

I still miss a "this driver will be called ..." message here, as it is used 
e.g. by the entry before:

>  	  To compile this driver as a module, choose M here: the
>  	  module will be called vmw_pvscsi.

Eike

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RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

> -----Original Message-----
> From: Rolf Eike Beer [mailto:eike-kernel@sf-tec.de]
> Sent: Thursday, January 26, 2012 12:17 PM
> To: KY Srinivasan
> Cc: gregkh@suse.de; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; virtualization@lists.osdl.org; ohering@suse.com;
> jbottomley@parallels.com; hch@infradead.org; linux-scsi@vger.kernel.org
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> Am Mittwoch 25 Januar 2012, 10:29:47 schrieb K. Y. Srinivasan:
> > The storage driver (storvsc_drv.c) handles all block storage devices
> > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > staging tree for a while and this patch moves it out of the staging area.
> >
> > This patch is based on the storvsc patches that are already on Greg's queue
> > for the staging tree. This patch-set addressed Christoph's review comments.
> > If need be, I can re-send this patch-set in Greg's queue
> > or I can  send the fully patched storvsc_drv.c.
> >
> > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > ---
> >  drivers/scsi/Kconfig                       |    7 +++++++
> >  drivers/scsi/Makefile                      |    3 +++
> >  drivers/{staging/hv => scsi}/storvsc_drv.c |    0
> >  3 files changed, 10 insertions(+), 0 deletions(-)
> >  rename drivers/{staging/hv => scsi}/storvsc_drv.c (100%)
> >
> > diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> > index 16570aa..d3d18e8 100644
> > --- a/drivers/scsi/Kconfig
> > +++ b/drivers/scsi/Kconfig
> > @@ -662,6 +662,13 @@ config VMWARE_PVSCSI
> >  	  To compile this driver as a module, choose M here: the
> >  	  module will be called vmw_pvscsi.
> >
> > +config HYPERV_STORAGE
> > +	tristate "Microsoft Hyper-V virtual storage driver"
> > +	depends on SCSI && HYPERV
> > +	default HYPERV
> > +	help
> > +	  Select this option to enable the Hyper-V virtual storage driver.
> > +
> >  config LIBFC
> >  	tristate "LibFC module"
> >  	select SCSI_FC_ATTRS
> > diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
> > index 2b88749..e4c1a69 100644
> 
> I still miss a "this driver will be called ..." message here, as it is used
> e.g. by the entry before:

After I moved the file to the scsi directory, in my haste I forgot to git add
the file. Sorry for the confusion; I will send out the corrected patches soon.

Regards,

K. Y

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

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> -----Original Message-----
> From: James Bottomley [mailto:jbottomley@parallels.com]
> Sent: Monday, February 13, 2012 2:29 PM
> To: Greg KH
> Cc: KY Srinivasan; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> scsi@vger.kernel.org
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Fri, 2012-02-10 at 10:02 -0800, Greg KH wrote:
> > On Thu, Feb 09, 2012 at 02:14:48PM -0800, K. Y. Srinivasan wrote:
> > > The storage driver (storvsc_drv.c) handles all block storage devices
> > > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > > staging tree for a while and this patch moves it out of the staging area.
> > >
> > > James was willing to apply this patch during the 3.3-rc phase and a decision
> > > was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> > > patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
> > > I am sending this patch to move this driver out of staging. Based on James'
> > > recommendation, this patch gets rid of the unneeded files in the staging/hv
> > > directory.
> > >
> > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > > ---
> > >  drivers/scsi/Kconfig                       |    7 +++++++
> > >  drivers/scsi/Makefile                      |    3 +++
> > >  drivers/{staging/hv => scsi}/storvsc_drv.c |    0
> > >  drivers/staging/Kconfig                    |    2 --
> > >  drivers/staging/Makefile                   |    1 -
> > >  drivers/staging/hv/Kconfig                 |    5 -----
> > >  drivers/staging/hv/Makefile                |    3 ---
> > >  drivers/staging/hv/TODO                    |    5 -----
> > >  8 files changed, 10 insertions(+), 16 deletions(-)
> > >  rename drivers/{staging/hv => scsi}/storvsc_drv.c (100%)
> > >  delete mode 100644 drivers/staging/hv/Kconfig
> > >  delete mode 100644 drivers/staging/hv/Makefile
> > >  delete mode 100644 drivers/staging/hv/TODO
> >
> > James, can I add your Acked-by: for this patch?
> 
> Yes ... i finally managed to pull your tree down and verify it.
> 
> Acked-by: James Bottomley <JBottomley@Parallels.com>

Thank you.

K. Y
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Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[James Bottomley]

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[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1919 bytes --]

On Fri, 2012-02-10 at 10:02 -0800, Greg KH wrote:
> On Thu, Feb 09, 2012 at 02:14:48PM -0800, K. Y. Srinivasan wrote:
> > The storage driver (storvsc_drv.c) handles all block storage devices
> > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > staging tree for a while and this patch moves it out of the staging area.
> > 
> > James was willing to apply this patch during the 3.3-rc phase and a decision
> > was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> > patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
> > I am sending this patch to move this driver out of staging. Based on James'
> > recommendation, this patch gets rid of the unneeded files in the staging/hv
> > directory.
> > 
> > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > ---
> >  drivers/scsi/Kconfig                       |    7 +++++++
> >  drivers/scsi/Makefile                      |    3 +++
> >  drivers/{staging/hv => scsi}/storvsc_drv.c |    0
> >  drivers/staging/Kconfig                    |    2 --
> >  drivers/staging/Makefile                   |    1 -
> >  drivers/staging/hv/Kconfig                 |    5 -----
> >  drivers/staging/hv/Makefile                |    3 ---
> >  drivers/staging/hv/TODO                    |    5 -----
> >  8 files changed, 10 insertions(+), 16 deletions(-)
> >  rename drivers/{staging/hv => scsi}/storvsc_drv.c (100%)
> >  delete mode 100644 drivers/staging/hv/Kconfig
> >  delete mode 100644 drivers/staging/hv/Makefile
> >  delete mode 100644 drivers/staging/hv/TODO
> 
> James, can I add your Acked-by: for this patch?

Yes ... i finally managed to pull your tree down and verify it.

Acked-by: James Bottomley <JBottomley@Parallels.com>

James

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RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Friday, February 10, 2012 1:02 PM
> To: KY Srinivasan; jbottomley@parallels.com
> Cc: linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> scsi@vger.kernel.org
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Thu, Feb 09, 2012 at 02:14:48PM -0800, K. Y. Srinivasan wrote:
> > The storage driver (storvsc_drv.c) handles all block storage devices
> > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > staging tree for a while and this patch moves it out of the staging area.
> >
> > James was willing to apply this patch during the 3.3-rc phase and a decision
> > was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> > patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
> > I am sending this patch to move this driver out of staging. Based on James'
> > recommendation, this patch gets rid of the unneeded files in the staging/hv
> > directory.
> >
> > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > ---
> >  drivers/scsi/Kconfig                       |    7 +++++++
> >  drivers/scsi/Makefile                      |    3 +++
> >  drivers/{staging/hv => scsi}/storvsc_drv.c |    0
> >  drivers/staging/Kconfig                    |    2 --
> >  drivers/staging/Makefile                   |    1 -
> >  drivers/staging/hv/Kconfig                 |    5 -----
> >  drivers/staging/hv/Makefile                |    3 ---
> >  drivers/staging/hv/TODO                    |    5 -----
> >  8 files changed, 10 insertions(+), 16 deletions(-)
> >  rename drivers/{staging/hv => scsi}/storvsc_drv.c (100%)
> >  delete mode 100644 drivers/staging/hv/Kconfig
> >  delete mode 100644 drivers/staging/hv/Makefile
> >  delete mode 100644 drivers/staging/hv/TODO
> 
> James, can I add your Acked-by: for this patch?

James,
Based on my understanding of your comments, I think this is what you
wanted. So, what is the verdict.

Regards,

K. Y. 

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[Greg KH]

On Thu, Feb 09, 2012 at 02:14:48PM -0800, K. Y. Srinivasan wrote:
> The storage driver (storvsc_drv.c) handles all block storage devices
> assigned to Linux guests hosted on Hyper-V. This driver has been in the
> staging tree for a while and this patch moves it out of the staging area.
> 
> James was willing to apply this patch during the 3.3-rc phase and a decision
> was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
> I am sending this patch to move this driver out of staging. Based on James'
> recommendation, this patch gets rid of the unneeded files in the staging/hv
> directory.
> 
> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> ---
>  drivers/scsi/Kconfig                       |    7 +++++++
>  drivers/scsi/Makefile                      |    3 +++
>  drivers/{staging/hv => scsi}/storvsc_drv.c |    0
>  drivers/staging/Kconfig                    |    2 --
>  drivers/staging/Makefile                   |    1 -
>  drivers/staging/hv/Kconfig                 |    5 -----
>  drivers/staging/hv/Makefile                |    3 ---
>  drivers/staging/hv/TODO                    |    5 -----
>  8 files changed, 10 insertions(+), 16 deletions(-)
>  rename drivers/{staging/hv => scsi}/storvsc_drv.c (100%)
>  delete mode 100644 drivers/staging/hv/Kconfig
>  delete mode 100644 drivers/staging/hv/Makefile
>  delete mode 100644 drivers/staging/hv/TODO

James, can I add your Acked-by: for this patch?

thanks,

greg k-h

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

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> -----Original Message-----
> From: James Bottomley [mailto:James.Bottomley@HansenPartnership.com]
> Sent: Thursday, February 09, 2012 3:46 PM
> To: KY Srinivasan
> Cc: Greg KH; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> scsi@vger.kernel.org
> Subject: RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Thu, 2012-02-09 at 20:43 +0000, KY Srinivasan wrote:
> >
> > > -----Original Message-----
> > > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > > Sent: Thursday, February 09, 2012 3:24 PM
> > > To: James Bottomley
> > > Cc: KY Srinivasan; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org;
> > > virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> > > scsi@vger.kernel.org
> > > Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of
> the
> > > staging area
> > >
> > > On Thu, Feb 09, 2012 at 02:18:38PM -0600, James Bottomley wrote:
> > > > On Thu, 2012-02-09 at 12:04 -0800, Greg KH wrote:
> > > > > On Thu, Feb 09, 2012 at 12:04:11PM -0800, K. Y. Srinivasan wrote:
> > > > > > The storage driver (storvsc_drv.c) handles all block storage devices
> > > > > > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > > > > > staging tree for a while and this patch moves it out of the staging area.
> > > > > > As per Greg's recommendation, this patch makes no changes to the
> > > staging/hv
> > > > > > directory. Once the driver moves out of staging, we will cleanup the
> > > > > > staging/hv directory.
> > > > > >
> > > > > > James was willing to apply this patch during the 3.3-rc phase and a
> decision
> > > > > > was taken to defer this to 3.4 since Greg had queued up a bunch of
> storvsc
> > > > > > patches for 3.4. Now that Greg has applied all of the pending storvsc
> > > patches,
> > > > > > I am re-sending this patch to move this driver out of staging.
> > > > > >
> > > > > >
> > > > > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > > > > > ---
> > > > > >  drivers/scsi/Kconfig       |    7 +
> > > > > >  drivers/scsi/Makefile      |    3 +
> > > > > >  drivers/scsi/storvsc_drv.c | 1548
> > > ++++++++++++++++++++++++++++++++++++++++++++
> > > > > >  3 files changed, 1558 insertions(+), 0 deletions(-)
> > > > > >  create mode 100644 drivers/scsi/storvsc_drv.c
> > > > >
> > > > > James, any objection to me applying this to the staging-next tree, and
> > > > > at the same time, deleting this version of the driver from the
> > > > > drivers/staging/hv/ directory?
> > > >
> > > > Well, yes, it has the same build failure as the previous one and that
> > > > will make it non bisectable.
> > >
> > > Ah, that would make things a bit difficult, KY, please test your
> > > patches...
> >
> > Greg,
> >
> > I pulled down your staging tree earlier today that had all the storvsc patches
> that you
> > checked in yesterday, applied this patch and built it (successfully).
> 
> You're leaving remnants in staging.
> 
> Move the damn thing and pull the config options from staging when you
> put them in SCSI.

James,

I have sent out a revised patch that does exactly what you are suggesting here.
If this is what you were looking for please ACK it.

Regards,

K. Y

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[PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[K. Y. Srinivasan]

The storage driver (storvsc_drv.c) handles all block storage devices
assigned to Linux guests hosted on Hyper-V. This driver has been in the
staging tree for a while and this patch moves it out of the staging area.

James was willing to apply this patch during the 3.3-rc phase and a decision
was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
I am sending this patch to move this driver out of staging. Based on James'
recommendation, this patch gets rid of the unneeded files in the staging/hv
directory.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/scsi/Kconfig                       |    7 +++++++
 drivers/scsi/Makefile                      |    3 +++
 drivers/{staging/hv => scsi}/storvsc_drv.c |    0
 drivers/staging/Kconfig                    |    2 --
 drivers/staging/Makefile                   |    1 -
 drivers/staging/hv/Kconfig                 |    5 -----
 drivers/staging/hv/Makefile                |    3 ---
 drivers/staging/hv/TODO                    |    5 -----
 8 files changed, 10 insertions(+), 16 deletions(-)
 rename drivers/{staging/hv => scsi}/storvsc_drv.c (100%)
 delete mode 100644 drivers/staging/hv/Kconfig
 delete mode 100644 drivers/staging/hv/Makefile
 delete mode 100644 drivers/staging/hv/TODO

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 16570aa..d3d18e8 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -662,6 +662,13 @@ config VMWARE_PVSCSI
 	  To compile this driver as a module, choose M here: the
 	  module will be called vmw_pvscsi.
 
+config HYPERV_STORAGE
+	tristate "Microsoft Hyper-V virtual storage driver"
+	depends on SCSI && HYPERV
+	default HYPERV
+	help
+	  Select this option to enable the Hyper-V virtual storage driver.
+
 config LIBFC
 	tristate "LibFC module"
 	select SCSI_FC_ATTRS
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 2b88749..e4c1a69 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -142,6 +142,7 @@ obj-$(CONFIG_SCSI_BNX2_ISCSI)	+= libiscsi.o bnx2i/
 obj-$(CONFIG_BE2ISCSI)		+= libiscsi.o be2iscsi/
 obj-$(CONFIG_SCSI_PMCRAID)	+= pmcraid.o
 obj-$(CONFIG_VMWARE_PVSCSI)	+= vmw_pvscsi.o
+obj-$(CONFIG_HYPERV_STORAGE)	+= hv_storvsc.o
 
 obj-$(CONFIG_ARM)		+= arm/
 
@@ -170,6 +171,8 @@ scsi_mod-$(CONFIG_SCSI_PROC_FS)	+= scsi_proc.o
 scsi_mod-y			+= scsi_trace.o
 scsi_mod-$(CONFIG_PM)		+= scsi_pm.o
 
+hv_storvsc-y			:= storvsc_drv.o
+
 scsi_tgt-y			+= scsi_tgt_lib.o scsi_tgt_if.o
 
 sd_mod-objs	:= sd.o
diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
similarity index 100%
rename from drivers/staging/hv/storvsc_drv.c
rename to drivers/scsi/storvsc_drv.c
diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 783bc0a..eb914ce 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -78,8 +78,6 @@ source "drivers/staging/vt6655/Kconfig"
 
 source "drivers/staging/vt6656/Kconfig"
 
-source "drivers/staging/hv/Kconfig"
-
 source "drivers/staging/vme/Kconfig"
 
 source "drivers/staging/sep/Kconfig"
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index 077a3f3..e6f14f5 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -30,7 +30,6 @@ obj-$(CONFIG_USB_SERIAL_QUATECH_USB2)	+= quatech_usb2/
 obj-$(CONFIG_OCTEON_ETHERNET)	+= octeon/
 obj-$(CONFIG_VT6655)		+= vt6655/
 obj-$(CONFIG_VT6656)		+= vt6656/
-obj-$(CONFIG_HYPERV)		+= hv/
 obj-$(CONFIG_VME_BUS)		+= vme/
 obj-$(CONFIG_DX_SEP)            += sep/
 obj-$(CONFIG_IIO)		+= iio/
diff --git a/drivers/staging/hv/Kconfig b/drivers/staging/hv/Kconfig
deleted file mode 100644
index 60ac479..0000000
--- a/drivers/staging/hv/Kconfig
+++ /dev/null
@@ -1,5 +0,0 @@
-config HYPERV_STORAGE
-	tristate "Microsoft Hyper-V virtual storage driver"
-	depends on HYPERV && SCSI
-	help
-	 Select this option to enable the Hyper-V virtual storage driver.
diff --git a/drivers/staging/hv/Makefile b/drivers/staging/hv/Makefile
deleted file mode 100644
index af95a6b..0000000
--- a/drivers/staging/hv/Makefile
+++ /dev/null
@@ -1,3 +0,0 @@
-obj-$(CONFIG_HYPERV_STORAGE)	+= hv_storvsc.o
-
-hv_storvsc-y := storvsc_drv.o
diff --git a/drivers/staging/hv/TODO b/drivers/staging/hv/TODO
deleted file mode 100644
index dea7d92..0000000
--- a/drivers/staging/hv/TODO
+++ /dev/null
@@ -1,5 +0,0 @@
-TODO:
-	- audit the scsi driver
-
-Please send patches for this code to Greg Kroah-Hartman <gregkh@suse.de>,
-Haiyang Zhang <haiyangz@microsoft.com>, and K. Y. Srinivasan <kys@microsoft.com>
-- 
1.7.4.1

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

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[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 3429 bytes --]



> -----Original Message-----
> From: James Bottomley [mailto:James.Bottomley@HansenPartnership.com]
> Sent: Thursday, February 09, 2012 3:46 PM
> To: KY Srinivasan
> Cc: Greg KH; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> scsi@vger.kernel.org
> Subject: RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Thu, 2012-02-09 at 20:43 +0000, KY Srinivasan wrote:
> >
> > > -----Original Message-----
> > > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > > Sent: Thursday, February 09, 2012 3:24 PM
> > > To: James Bottomley
> > > Cc: KY Srinivasan; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org;
> > > virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> > > scsi@vger.kernel.org
> > > Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of
> the
> > > staging area
> > >
> > > On Thu, Feb 09, 2012 at 02:18:38PM -0600, James Bottomley wrote:
> > > > On Thu, 2012-02-09 at 12:04 -0800, Greg KH wrote:
> > > > > On Thu, Feb 09, 2012 at 12:04:11PM -0800, K. Y. Srinivasan wrote:
> > > > > > The storage driver (storvsc_drv.c) handles all block storage devices
> > > > > > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > > > > > staging tree for a while and this patch moves it out of the staging area.
> > > > > > As per Greg's recommendation, this patch makes no changes to the
> > > staging/hv
> > > > > > directory. Once the driver moves out of staging, we will cleanup the
> > > > > > staging/hv directory.
> > > > > >
> > > > > > James was willing to apply this patch during the 3.3-rc phase and a
> decision
> > > > > > was taken to defer this to 3.4 since Greg had queued up a bunch of
> storvsc
> > > > > > patches for 3.4. Now that Greg has applied all of the pending storvsc
> > > patches,
> > > > > > I am re-sending this patch to move this driver out of staging.
> > > > > >
> > > > > >
> > > > > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > > > > > ---
> > > > > >  drivers/scsi/Kconfig       |    7 +
> > > > > >  drivers/scsi/Makefile      |    3 +
> > > > > >  drivers/scsi/storvsc_drv.c | 1548
> > > ++++++++++++++++++++++++++++++++++++++++++++
> > > > > >  3 files changed, 1558 insertions(+), 0 deletions(-)
> > > > > >  create mode 100644 drivers/scsi/storvsc_drv.c
> > > > >
> > > > > James, any objection to me applying this to the staging-next tree, and
> > > > > at the same time, deleting this version of the driver from the
> > > > > drivers/staging/hv/ directory?
> > > >
> > > > Well, yes, it has the same build failure as the previous one and that
> > > > will make it non bisectable.
> > >
> > > Ah, that would make things a bit difficult, KY, please test your
> > > patches...
> >
> > Greg,
> >
> > I pulled down your staging tree earlier today that had all the storvsc patches
> that you
> > checked in yesterday, applied this patch and built it (successfully).
> 
> You're leaving remnants in staging.
> 
> Move the damn thing and pull the config options from staging when you
> put them in SCSI.

I have now also sent out a patch that does what you are suggesting here. 

Regards,

K. Y
 

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RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 3635 bytes --]



> -----Original Message-----
> From: James Bottomley [mailto:James.Bottomley@HansenPartnership.com]
> Sent: Thursday, February 09, 2012 3:46 PM
> To: KY Srinivasan
> Cc: Greg KH; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> scsi@vger.kernel.org
> Subject: RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Thu, 2012-02-09 at 20:43 +0000, KY Srinivasan wrote:
> >
> > > -----Original Message-----
> > > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > > Sent: Thursday, February 09, 2012 3:24 PM
> > > To: James Bottomley
> > > Cc: KY Srinivasan; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org;
> > > virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> > > scsi@vger.kernel.org
> > > Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of
> the
> > > staging area
> > >
> > > On Thu, Feb 09, 2012 at 02:18:38PM -0600, James Bottomley wrote:
> > > > On Thu, 2012-02-09 at 12:04 -0800, Greg KH wrote:
> > > > > On Thu, Feb 09, 2012 at 12:04:11PM -0800, K. Y. Srinivasan wrote:
> > > > > > The storage driver (storvsc_drv.c) handles all block storage devices
> > > > > > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > > > > > staging tree for a while and this patch moves it out of the staging area.
> > > > > > As per Greg's recommendation, this patch makes no changes to the
> > > staging/hv
> > > > > > directory. Once the driver moves out of staging, we will cleanup the
> > > > > > staging/hv directory.
> > > > > >
> > > > > > James was willing to apply this patch during the 3.3-rc phase and a
> decision
> > > > > > was taken to defer this to 3.4 since Greg had queued up a bunch of
> storvsc
> > > > > > patches for 3.4. Now that Greg has applied all of the pending storvsc
> > > patches,
> > > > > > I am re-sending this patch to move this driver out of staging.
> > > > > >
> > > > > >
> > > > > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > > > > > ---
> > > > > >  drivers/scsi/Kconfig       |    7 +
> > > > > >  drivers/scsi/Makefile      |    3 +
> > > > > >  drivers/scsi/storvsc_drv.c | 1548
> > > ++++++++++++++++++++++++++++++++++++++++++++
> > > > > >  3 files changed, 1558 insertions(+), 0 deletions(-)
> > > > > >  create mode 100644 drivers/scsi/storvsc_drv.c
> > > > >
> > > > > James, any objection to me applying this to the staging-next tree, and
> > > > > at the same time, deleting this version of the driver from the
> > > > > drivers/staging/hv/ directory?
> > > >
> > > > Well, yes, it has the same build failure as the previous one and that
> > > > will make it non bisectable.
> > >
> > > Ah, that would make things a bit difficult, KY, please test your
> > > patches...
> >
> > Greg,
> >
> > I pulled down your staging tree earlier today that had all the storvsc patches
> that you
> > checked in yesterday, applied this patch and built it (successfully).
> 
> You're leaving remnants in staging.
> 
> Move the damn thing and pull the config options from staging when you
> put them in SCSI.

Greg had recommended that the patch moving the driver should not delete the contents
in the staging directory and that he (Greg) would clean up the staging directory. Greg, let me
know if you want me to send you a patch that includes getting rid of the stuff from the staging area.

Regards,

K. Y

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RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[James Bottomley]

On Thu, 2012-02-09 at 20:43 +0000, KY Srinivasan wrote:
> 
> > -----Original Message-----
> > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > Sent: Thursday, February 09, 2012 3:24 PM
> > To: James Bottomley
> > Cc: KY Srinivasan; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> > virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> > scsi@vger.kernel.org
> > Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> > staging area
> > 
> > On Thu, Feb 09, 2012 at 02:18:38PM -0600, James Bottomley wrote:
> > > On Thu, 2012-02-09 at 12:04 -0800, Greg KH wrote:
> > > > On Thu, Feb 09, 2012 at 12:04:11PM -0800, K. Y. Srinivasan wrote:
> > > > > The storage driver (storvsc_drv.c) handles all block storage devices
> > > > > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > > > > staging tree for a while and this patch moves it out of the staging area.
> > > > > As per Greg's recommendation, this patch makes no changes to the
> > staging/hv
> > > > > directory. Once the driver moves out of staging, we will cleanup the
> > > > > staging/hv directory.
> > > > >
> > > > > James was willing to apply this patch during the 3.3-rc phase and a decision
> > > > > was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> > > > > patches for 3.4. Now that Greg has applied all of the pending storvsc
> > patches,
> > > > > I am re-sending this patch to move this driver out of staging.
> > > > >
> > > > >
> > > > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > > > > ---
> > > > >  drivers/scsi/Kconfig       |    7 +
> > > > >  drivers/scsi/Makefile      |    3 +
> > > > >  drivers/scsi/storvsc_drv.c | 1548
> > ++++++++++++++++++++++++++++++++++++++++++++
> > > > >  3 files changed, 1558 insertions(+), 0 deletions(-)
> > > > >  create mode 100644 drivers/scsi/storvsc_drv.c
> > > >
> > > > James, any objection to me applying this to the staging-next tree, and
> > > > at the same time, deleting this version of the driver from the
> > > > drivers/staging/hv/ directory?
> > >
> > > Well, yes, it has the same build failure as the previous one and that
> > > will make it non bisectable.
> > 
> > Ah, that would make things a bit difficult, KY, please test your
> > patches...
> 
> Greg,
> 
> I pulled down your staging tree earlier today that had all the storvsc patches that you
> checked in yesterday, applied this patch and built it (successfully).

You're leaving remnants in staging.

Move the damn thing and pull the config options from staging when you
put them in SCSI.

James

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Thursday, February 09, 2012 3:24 PM
> To: James Bottomley
> Cc: KY Srinivasan; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> scsi@vger.kernel.org
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Thu, Feb 09, 2012 at 02:18:38PM -0600, James Bottomley wrote:
> > On Thu, 2012-02-09 at 12:04 -0800, Greg KH wrote:
> > > On Thu, Feb 09, 2012 at 12:04:11PM -0800, K. Y. Srinivasan wrote:
> > > > The storage driver (storvsc_drv.c) handles all block storage devices
> > > > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > > > staging tree for a while and this patch moves it out of the staging area.
> > > > As per Greg's recommendation, this patch makes no changes to the
> staging/hv
> > > > directory. Once the driver moves out of staging, we will cleanup the
> > > > staging/hv directory.
> > > >
> > > > James was willing to apply this patch during the 3.3-rc phase and a decision
> > > > was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> > > > patches for 3.4. Now that Greg has applied all of the pending storvsc
> patches,
> > > > I am re-sending this patch to move this driver out of staging.
> > > >
> > > >
> > > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > > > ---
> > > >  drivers/scsi/Kconfig       |    7 +
> > > >  drivers/scsi/Makefile      |    3 +
> > > >  drivers/scsi/storvsc_drv.c | 1548
> ++++++++++++++++++++++++++++++++++++++++++++
> > > >  3 files changed, 1558 insertions(+), 0 deletions(-)
> > > >  create mode 100644 drivers/scsi/storvsc_drv.c
> > >
> > > James, any objection to me applying this to the staging-next tree, and
> > > at the same time, deleting this version of the driver from the
> > > drivers/staging/hv/ directory?
> >
> > Well, yes, it has the same build failure as the previous one and that
> > will make it non bisectable.
> 
> Ah, that would make things a bit difficult, KY, please test your
> patches...

Greg,

I pulled down your staging tree earlier today that had all the storvsc patches that you
checked in yesterday, applied this patch and built it (successfully).

Regards,

K. Y

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[James Bottomley]

On Thu, 2012-02-09 at 20:21 +0000, KY Srinivasan wrote:
> 
> > -----Original Message-----
> > From: James Bottomley [mailto:James.Bottomley@HansenPartnership.com]
> > Sent: Thursday, February 09, 2012 3:19 PM
> > To: Greg KH
> > Cc: KY Srinivasan; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> > virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> > scsi@vger.kernel.org
> > Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> > staging area
> > 
> > On Thu, 2012-02-09 at 12:04 -0800, Greg KH wrote:
> > > On Thu, Feb 09, 2012 at 12:04:11PM -0800, K. Y. Srinivasan wrote:
> > > > The storage driver (storvsc_drv.c) handles all block storage devices
> > > > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > > > staging tree for a while and this patch moves it out of the staging area.
> > > > As per Greg's recommendation, this patch makes no changes to the
> > staging/hv
> > > > directory. Once the driver moves out of staging, we will cleanup the
> > > > staging/hv directory.
> > > >
> > > > James was willing to apply this patch during the 3.3-rc phase and a decision
> > > > was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> > > > patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
> > > > I am re-sending this patch to move this driver out of staging.
> > > >
> > > >
> > > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > > > ---
> > > >  drivers/scsi/Kconfig       |    7 +
> > > >  drivers/scsi/Makefile      |    3 +
> > > >  drivers/scsi/storvsc_drv.c | 1548
> > ++++++++++++++++++++++++++++++++++++++++++++
> > > >  3 files changed, 1558 insertions(+), 0 deletions(-)
> > > >  create mode 100644 drivers/scsi/storvsc_drv.c
> > >
> > > James, any objection to me applying this to the staging-next tree, and
> > > at the same time, deleting this version of the driver from the
> > > drivers/staging/hv/ directory?
> > 
> > Well, yes, it has the same build failure as the previous one and that
> > will make it non bisectable.
> 
> James,
> 
> What build failure is this. I just pulled down Greg's tree earlier today and applied this
> patch and built it.

This one

marc.info/?l=linux-driver-devel&m=132760187731205

James

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[Greg KH]

On Thu, Feb 09, 2012 at 02:18:38PM -0600, James Bottomley wrote:
> On Thu, 2012-02-09 at 12:04 -0800, Greg KH wrote:
> > On Thu, Feb 09, 2012 at 12:04:11PM -0800, K. Y. Srinivasan wrote:
> > > The storage driver (storvsc_drv.c) handles all block storage devices
> > > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > > staging tree for a while and this patch moves it out of the staging area.
> > > As per Greg's recommendation, this patch makes no changes to the staging/hv
> > > directory. Once the driver moves out of staging, we will cleanup the
> > > staging/hv directory.
> > > 
> > > James was willing to apply this patch during the 3.3-rc phase and a decision
> > > was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> > > patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
> > > I am re-sending this patch to move this driver out of staging.
> > > 
> > > 
> > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > > ---
> > >  drivers/scsi/Kconfig       |    7 +
> > >  drivers/scsi/Makefile      |    3 +
> > >  drivers/scsi/storvsc_drv.c | 1548 ++++++++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 1558 insertions(+), 0 deletions(-)
> > >  create mode 100644 drivers/scsi/storvsc_drv.c
> > 
> > James, any objection to me applying this to the staging-next tree, and
> > at the same time, deleting this version of the driver from the
> > drivers/staging/hv/ directory?
> 
> Well, yes, it has the same build failure as the previous one and that
> will make it non bisectable.

Ah, that would make things a bit difficult, KY, please test your
patches...

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

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> -----Original Message-----
> From: James Bottomley [mailto:James.Bottomley@HansenPartnership.com]
> Sent: Thursday, February 09, 2012 3:19 PM
> To: Greg KH
> Cc: KY Srinivasan; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> virtualization@lists.osdl.org; ohering@suse.com; hch@infradead.org; linux-
> scsi@vger.kernel.org
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Thu, 2012-02-09 at 12:04 -0800, Greg KH wrote:
> > On Thu, Feb 09, 2012 at 12:04:11PM -0800, K. Y. Srinivasan wrote:
> > > The storage driver (storvsc_drv.c) handles all block storage devices
> > > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > > staging tree for a while and this patch moves it out of the staging area.
> > > As per Greg's recommendation, this patch makes no changes to the
> staging/hv
> > > directory. Once the driver moves out of staging, we will cleanup the
> > > staging/hv directory.
> > >
> > > James was willing to apply this patch during the 3.3-rc phase and a decision
> > > was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> > > patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
> > > I am re-sending this patch to move this driver out of staging.
> > >
> > >
> > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > > ---
> > >  drivers/scsi/Kconfig       |    7 +
> > >  drivers/scsi/Makefile      |    3 +
> > >  drivers/scsi/storvsc_drv.c | 1548
> ++++++++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 1558 insertions(+), 0 deletions(-)
> > >  create mode 100644 drivers/scsi/storvsc_drv.c
> >
> > James, any objection to me applying this to the staging-next tree, and
> > at the same time, deleting this version of the driver from the
> > drivers/staging/hv/ directory?
> 
> Well, yes, it has the same build failure as the previous one and that
> will make it non bisectable.

James,

What build failure is this. I just pulled down Greg's tree earlier today and applied this
patch and built it.

Regards,

K. Y 
 

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Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[James Bottomley]

On Thu, 2012-02-09 at 12:04 -0800, Greg KH wrote:
> On Thu, Feb 09, 2012 at 12:04:11PM -0800, K. Y. Srinivasan wrote:
> > The storage driver (storvsc_drv.c) handles all block storage devices
> > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > staging tree for a while and this patch moves it out of the staging area.
> > As per Greg's recommendation, this patch makes no changes to the staging/hv
> > directory. Once the driver moves out of staging, we will cleanup the
> > staging/hv directory.
> > 
> > James was willing to apply this patch during the 3.3-rc phase and a decision
> > was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> > patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
> > I am re-sending this patch to move this driver out of staging.
> > 
> > 
> > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> > ---
> >  drivers/scsi/Kconfig       |    7 +
> >  drivers/scsi/Makefile      |    3 +
> >  drivers/scsi/storvsc_drv.c | 1548 ++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 1558 insertions(+), 0 deletions(-)
> >  create mode 100644 drivers/scsi/storvsc_drv.c
> 
> James, any objection to me applying this to the staging-next tree, and
> at the same time, deleting this version of the driver from the
> drivers/staging/hv/ directory?

Well, yes, it has the same build failure as the previous one and that
will make it non bisectable.

James

[PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[K. Y. Srinivasan]

The storage driver (storvsc_drv.c) handles all block storage devices
assigned to Linux guests hosted on Hyper-V. This driver has been in the
staging tree for a while and this patch moves it out of the staging area.
As per Greg's recommendation, this patch makes no changes to the staging/hv
directory. Once the driver moves out of staging, we will cleanup the
staging/hv directory.

James was willing to apply this patch during the 3.3-rc phase and a decision
was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
I am re-sending this patch to move this driver out of staging.


Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/scsi/Kconfig       |    7 +
 drivers/scsi/Makefile      |    3 +
 drivers/scsi/storvsc_drv.c | 1548 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1558 insertions(+), 0 deletions(-)
 create mode 100644 drivers/scsi/storvsc_drv.c

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 06ea3bc..4910269 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -662,6 +662,13 @@ config VMWARE_PVSCSI
 	  To compile this driver as a module, choose M here: the
 	  module will be called vmw_pvscsi.
 
+config HYPERV_STORAGE
+	tristate "Microsoft Hyper-V virtual storage driver"
+	depends on SCSI && HYPERV
+	default HYPERV
+	help
+	  Select this option to enable the Hyper-V virtual storage driver.
+
 config LIBFC
 	tristate "LibFC module"
 	select SCSI_FC_ATTRS
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 2b88749..e4c1a69 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -142,6 +142,7 @@ obj-$(CONFIG_SCSI_BNX2_ISCSI)	+= libiscsi.o bnx2i/
 obj-$(CONFIG_BE2ISCSI)		+= libiscsi.o be2iscsi/
 obj-$(CONFIG_SCSI_PMCRAID)	+= pmcraid.o
 obj-$(CONFIG_VMWARE_PVSCSI)	+= vmw_pvscsi.o
+obj-$(CONFIG_HYPERV_STORAGE)	+= hv_storvsc.o
 
 obj-$(CONFIG_ARM)		+= arm/
 
@@ -170,6 +171,8 @@ scsi_mod-$(CONFIG_SCSI_PROC_FS)	+= scsi_proc.o
 scsi_mod-y			+= scsi_trace.o
 scsi_mod-$(CONFIG_PM)		+= scsi_pm.o
 
+hv_storvsc-y			:= storvsc_drv.o
+
 scsi_tgt-y			+= scsi_tgt_lib.o scsi_tgt_if.o
 
 sd_mod-objs	:= sd.o
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
new file mode 100644
index 0000000..695ffc3
--- /dev/null
+++ b/drivers/scsi/storvsc_drv.c
@@ -0,0 +1,1548 @@
+/*
+ * Copyright (c) 2009, Microsoft Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Authors:
+ *   Haiyang Zhang <haiyangz@microsoft.com>
+ *   Hank Janssen  <hjanssen@microsoft.com>
+ *   K. Y. Srinivasan <kys@microsoft.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/hyperv.h>
+#include <linux/mempool.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_devinfo.h>
+#include <scsi/scsi_dbg.h>
+
+/*
+ * All wire protocol details (storage protocol between the guest and the host)
+ * are consolidated here.
+ *
+ * Begin protocol definitions.
+ */
+
+/*
+ * Version history:
+ * V1 Beta: 0.1
+ * V1 RC < 2008/1/31: 1.0
+ * V1 RC > 2008/1/31:  2.0
+ * Win7: 4.2
+ */
+
+#define VMSTOR_CURRENT_MAJOR  4
+#define VMSTOR_CURRENT_MINOR  2
+
+
+/*  Packet structure describing virtual storage requests. */
+enum vstor_packet_operation {
+	VSTOR_OPERATION_COMPLETE_IO		= 1,
+	VSTOR_OPERATION_REMOVE_DEVICE		= 2,
+	VSTOR_OPERATION_EXECUTE_SRB		= 3,
+	VSTOR_OPERATION_RESET_LUN		= 4,
+	VSTOR_OPERATION_RESET_ADAPTER		= 5,
+	VSTOR_OPERATION_RESET_BUS		= 6,
+	VSTOR_OPERATION_BEGIN_INITIALIZATION	= 7,
+	VSTOR_OPERATION_END_INITIALIZATION	= 8,
+	VSTOR_OPERATION_QUERY_PROTOCOL_VERSION	= 9,
+	VSTOR_OPERATION_QUERY_PROPERTIES	= 10,
+	VSTOR_OPERATION_ENUMERATE_BUS		= 11,
+	VSTOR_OPERATION_MAXIMUM			= 11
+};
+
+/*
+ * Platform neutral description of a scsi request -
+ * this remains the same across the write regardless of 32/64 bit
+ * note: it's patterned off the SCSI_PASS_THROUGH structure
+ */
+#define STORVSC_MAX_CMD_LEN			0x10
+#define STORVSC_SENSE_BUFFER_SIZE		0x12
+#define STORVSC_MAX_BUF_LEN_WITH_PADDING	0x14
+
+struct vmscsi_request {
+	u16 length;
+	u8 srb_status;
+	u8 scsi_status;
+
+	u8  port_number;
+	u8  path_id;
+	u8  target_id;
+	u8  lun;
+
+	u8  cdb_length;
+	u8  sense_info_length;
+	u8  data_in;
+	u8  reserved;
+
+	u32 data_transfer_length;
+
+	union {
+		u8 cdb[STORVSC_MAX_CMD_LEN];
+		u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
+		u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
+	};
+} __attribute((packed));
+
+
+/*
+ * This structure is sent during the intialization phase to get the different
+ * properties of the channel.
+ */
+struct vmstorage_channel_properties {
+	u16 protocol_version;
+	u8  path_id;
+	u8 target_id;
+
+	/* Note: port number is only really known on the client side */
+	u32  port_number;
+	u32  flags;
+	u32   max_transfer_bytes;
+
+	/*
+	 * This id is unique for each channel and will correspond with
+	 * vendor specific data in the inquiry data.
+	 */
+
+	u64  unique_id;
+} __packed;
+
+/*  This structure is sent during the storage protocol negotiations. */
+struct vmstorage_protocol_version {
+	/* Major (MSW) and minor (LSW) version numbers. */
+	u16 major_minor;
+
+	/*
+	 * Revision number is auto-incremented whenever this file is changed
+	 * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
+	 * definitely indicate incompatibility--but it does indicate mismatched
+	 * builds.
+	 * This is only used on the windows side. Just set it to 0.
+	 */
+	u16 revision;
+} __packed;
+
+/* Channel Property Flags */
+#define STORAGE_CHANNEL_REMOVABLE_FLAG		0x1
+#define STORAGE_CHANNEL_EMULATED_IDE_FLAG	0x2
+
+struct vstor_packet {
+	/* Requested operation type */
+	enum vstor_packet_operation operation;
+
+	/*  Flags - see below for values */
+	u32 flags;
+
+	/* Status of the request returned from the server side. */
+	u32 status;
+
+	/* Data payload area */
+	union {
+		/*
+		 * Structure used to forward SCSI commands from the
+		 * client to the server.
+		 */
+		struct vmscsi_request vm_srb;
+
+		/* Structure used to query channel properties. */
+		struct vmstorage_channel_properties storage_channel_properties;
+
+		/* Used during version negotiations. */
+		struct vmstorage_protocol_version version;
+	};
+} __packed;
+
+/*
+ * Packet Flags:
+ *
+ * This flag indicates that the server should send back a completion for this
+ * packet.
+ */
+
+#define REQUEST_COMPLETION_FLAG	0x1
+
+/* Matches Windows-end */
+enum storvsc_request_type {
+	WRITE_TYPE = 0,
+	READ_TYPE,
+	UNKNOWN_TYPE,
+};
+
+/*
+ * SRB status codes and masks; a subset of the codes used here.
+ */
+
+#define SRB_STATUS_AUTOSENSE_VALID	0x80
+#define SRB_STATUS_INVALID_LUN	0x20
+#define SRB_STATUS_SUCCESS	0x01
+#define SRB_STATUS_ERROR	0x04
+
+/*
+ * This is the end of Protocol specific defines.
+ */
+
+
+/*
+ * We setup a mempool to allocate request structures for this driver
+ * on a per-lun basis. The following define specifies the number of
+ * elements in the pool.
+ */
+
+#define STORVSC_MIN_BUF_NR				64
+static int storvsc_ringbuffer_size = (20 * PAGE_SIZE);
+
+module_param(storvsc_ringbuffer_size, int, S_IRUGO);
+MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
+
+#define STORVSC_MAX_IO_REQUESTS				128
+
+/*
+ * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
+ * reality, the path/target is not used (ie always set to 0) so our
+ * scsi host adapter essentially has 1 bus with 1 target that contains
+ * up to 256 luns.
+ */
+#define STORVSC_MAX_LUNS_PER_TARGET			64
+#define STORVSC_MAX_TARGETS				1
+#define STORVSC_MAX_CHANNELS				1
+
+
+
+struct storvsc_cmd_request {
+	struct list_head entry;
+	struct scsi_cmnd *cmd;
+
+	unsigned int bounce_sgl_count;
+	struct scatterlist *bounce_sgl;
+
+	struct hv_device *device;
+
+	/* Synchronize the request/response if needed */
+	struct completion wait_event;
+
+	unsigned char *sense_buffer;
+	struct hv_multipage_buffer data_buffer;
+	struct vstor_packet vstor_packet;
+};
+
+
+/* A storvsc device is a device object that contains a vmbus channel */
+struct storvsc_device {
+	struct hv_device *device;
+
+	bool	 destroy;
+	bool	 drain_notify;
+	atomic_t num_outstanding_req;
+	struct Scsi_Host *host;
+
+	wait_queue_head_t waiting_to_drain;
+
+	/*
+	 * Each unique Port/Path/Target represents 1 channel ie scsi
+	 * controller. In reality, the pathid, targetid is always 0
+	 * and the port is set by us
+	 */
+	unsigned int port_number;
+	unsigned char path_id;
+	unsigned char target_id;
+
+	/* Used for vsc/vsp channel reset process */
+	struct storvsc_cmd_request init_request;
+	struct storvsc_cmd_request reset_request;
+};
+
+struct stor_mem_pools {
+	struct kmem_cache *request_pool;
+	mempool_t *request_mempool;
+};
+
+struct hv_host_device {
+	struct hv_device *dev;
+	unsigned int port;
+	unsigned char path;
+	unsigned char target;
+};
+
+struct storvsc_scan_work {
+	struct work_struct work;
+	struct Scsi_Host *host;
+	uint lun;
+};
+
+static void storvsc_bus_scan(struct work_struct *work)
+{
+	struct storvsc_scan_work *wrk;
+	int id, order_id;
+
+	wrk = container_of(work, struct storvsc_scan_work, work);
+	for (id = 0; id < wrk->host->max_id; ++id) {
+		if (wrk->host->reverse_ordering)
+			order_id = wrk->host->max_id - id - 1;
+		else
+			order_id = id;
+
+		scsi_scan_target(&wrk->host->shost_gendev, 0,
+				order_id, SCAN_WILD_CARD, 1);
+	}
+	kfree(wrk);
+}
+
+static void storvsc_remove_lun(struct work_struct *work)
+{
+	struct storvsc_scan_work *wrk;
+	struct scsi_device *sdev;
+
+	wrk = container_of(work, struct storvsc_scan_work, work);
+	if (!scsi_host_get(wrk->host))
+		goto done;
+
+	sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
+
+	if (sdev) {
+		scsi_remove_device(sdev);
+		scsi_device_put(sdev);
+	}
+	scsi_host_put(wrk->host);
+
+done:
+	kfree(wrk);
+}
+
+/*
+ * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
+ * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
+ */
+
+static inline u16 storvsc_get_version(u8 major, u8 minor)
+{
+	u16 version;
+
+	version = ((major << 8) | minor);
+	return version;
+}
+
+/*
+ * We can get incoming messages from the host that are not in response to
+ * messages that we have sent out. An example of this would be messages
+ * received by the guest to notify dynamic addition/removal of LUNs. To
+ * deal with potential race conditions where the driver may be in the
+ * midst of being unloaded when we might receive an unsolicited message
+ * from the host, we have implemented a mechanism to gurantee sequential
+ * consistency:
+ *
+ * 1) Once the device is marked as being destroyed, we will fail all
+ *    outgoing messages.
+ * 2) We permit incoming messages when the device is being destroyed,
+ *    only to properly account for messages already sent out.
+ */
+
+static inline struct storvsc_device *get_out_stor_device(
+					struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+
+	stor_device = hv_get_drvdata(device);
+
+	if (stor_device && stor_device->destroy)
+		stor_device = NULL;
+
+	return stor_device;
+}
+
+
+static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
+{
+	dev->drain_notify = true;
+	wait_event(dev->waiting_to_drain,
+		   atomic_read(&dev->num_outstanding_req) == 0);
+	dev->drain_notify = false;
+}
+
+static inline struct storvsc_device *get_in_stor_device(
+					struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+
+	stor_device = hv_get_drvdata(device);
+
+	if (!stor_device)
+		goto get_in_err;
+
+	/*
+	 * If the device is being destroyed; allow incoming
+	 * traffic only to cleanup outstanding requests.
+	 */
+
+	if (stor_device->destroy  &&
+		(atomic_read(&stor_device->num_outstanding_req) == 0))
+		stor_device = NULL;
+
+get_in_err:
+	return stor_device;
+
+}
+
+static void destroy_bounce_buffer(struct scatterlist *sgl,
+				  unsigned int sg_count)
+{
+	int i;
+	struct page *page_buf;
+
+	for (i = 0; i < sg_count; i++) {
+		page_buf = sg_page((&sgl[i]));
+		if (page_buf != NULL)
+			__free_page(page_buf);
+	}
+
+	kfree(sgl);
+}
+
+static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
+{
+	int i;
+
+	/* No need to check */
+	if (sg_count < 2)
+		return -1;
+
+	/* We have at least 2 sg entries */
+	for (i = 0; i < sg_count; i++) {
+		if (i == 0) {
+			/* make sure 1st one does not have hole */
+			if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
+				return i;
+		} else if (i == sg_count - 1) {
+			/* make sure last one does not have hole */
+			if (sgl[i].offset != 0)
+				return i;
+		} else {
+			/* make sure no hole in the middle */
+			if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
+				return i;
+		}
+	}
+	return -1;
+}
+
+static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
+						unsigned int sg_count,
+						unsigned int len,
+						int write)
+{
+	int i;
+	int num_pages;
+	struct scatterlist *bounce_sgl;
+	struct page *page_buf;
+	unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
+
+	num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
+
+	bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
+	if (!bounce_sgl)
+		return NULL;
+
+	for (i = 0; i < num_pages; i++) {
+		page_buf = alloc_page(GFP_ATOMIC);
+		if (!page_buf)
+			goto cleanup;
+		sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
+	}
+
+	return bounce_sgl;
+
+cleanup:
+	destroy_bounce_buffer(bounce_sgl, num_pages);
+	return NULL;
+}
+
+/* Assume the original sgl has enough room */
+static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
+					    struct scatterlist *bounce_sgl,
+					    unsigned int orig_sgl_count,
+					    unsigned int bounce_sgl_count)
+{
+	int i;
+	int j = 0;
+	unsigned long src, dest;
+	unsigned int srclen, destlen, copylen;
+	unsigned int total_copied = 0;
+	unsigned long bounce_addr = 0;
+	unsigned long dest_addr = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for (i = 0; i < orig_sgl_count; i++) {
+		dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
+					KM_IRQ0) + orig_sgl[i].offset;
+		dest = dest_addr;
+		destlen = orig_sgl[i].length;
+
+		if (bounce_addr == 0)
+			bounce_addr =
+			(unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
+							KM_IRQ0);
+
+		while (destlen) {
+			src = bounce_addr + bounce_sgl[j].offset;
+			srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
+
+			copylen = min(srclen, destlen);
+			memcpy((void *)dest, (void *)src, copylen);
+
+			total_copied += copylen;
+			bounce_sgl[j].offset += copylen;
+			destlen -= copylen;
+			dest += copylen;
+
+			if (bounce_sgl[j].offset == bounce_sgl[j].length) {
+				/* full */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+				j++;
+
+				/*
+				 * It is possible that the number of elements
+				 * in the bounce buffer may not be equal to
+				 * the number of elements in the original
+				 * scatter list. Handle this correctly.
+				 */
+
+				if (j == bounce_sgl_count) {
+					/*
+					 * We are done; cleanup and return.
+					 */
+					kunmap_atomic((void *)(dest_addr -
+							orig_sgl[i].offset),
+							KM_IRQ0);
+					local_irq_restore(flags);
+					return total_copied;
+				}
+
+				/* if we need to use another bounce buffer */
+				if (destlen || i != orig_sgl_count - 1)
+					bounce_addr =
+					(unsigned long)kmap_atomic(
+					sg_page((&bounce_sgl[j])), KM_IRQ0);
+			} else if (destlen == 0 && i == orig_sgl_count - 1) {
+				/* unmap the last bounce that is < PAGE_SIZE */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+			}
+		}
+
+		kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
+			      KM_IRQ0);
+	}
+
+	local_irq_restore(flags);
+
+	return total_copied;
+}
+
+/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
+static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
+					  struct scatterlist *bounce_sgl,
+					  unsigned int orig_sgl_count)
+{
+	int i;
+	int j = 0;
+	unsigned long src, dest;
+	unsigned int srclen, destlen, copylen;
+	unsigned int total_copied = 0;
+	unsigned long bounce_addr = 0;
+	unsigned long src_addr = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for (i = 0; i < orig_sgl_count; i++) {
+		src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
+				KM_IRQ0) + orig_sgl[i].offset;
+		src = src_addr;
+		srclen = orig_sgl[i].length;
+
+		if (bounce_addr == 0)
+			bounce_addr =
+			(unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
+						KM_IRQ0);
+
+		while (srclen) {
+			/* assume bounce offset always == 0 */
+			dest = bounce_addr + bounce_sgl[j].length;
+			destlen = PAGE_SIZE - bounce_sgl[j].length;
+
+			copylen = min(srclen, destlen);
+			memcpy((void *)dest, (void *)src, copylen);
+
+			total_copied += copylen;
+			bounce_sgl[j].length += copylen;
+			srclen -= copylen;
+			src += copylen;
+
+			if (bounce_sgl[j].length == PAGE_SIZE) {
+				/* full..move to next entry */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+				j++;
+
+				/* if we need to use another bounce buffer */
+				if (srclen || i != orig_sgl_count - 1)
+					bounce_addr =
+					(unsigned long)kmap_atomic(
+					sg_page((&bounce_sgl[j])), KM_IRQ0);
+
+			} else if (srclen == 0 && i == orig_sgl_count - 1) {
+				/* unmap the last bounce that is < PAGE_SIZE */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+			}
+		}
+
+		kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
+	}
+
+	local_irq_restore(flags);
+
+	return total_copied;
+}
+
+static int storvsc_channel_init(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	struct storvsc_cmd_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return -ENODEV;
+
+	request = &stor_device->init_request;
+	vstor_packet = &request->vstor_packet;
+
+	/*
+	 * Now, initiate the vsc/vsp initialization protocol on the open
+	 * channel
+	 */
+	memset(request, 0, sizeof(struct storvsc_cmd_request));
+	init_completion(&request->wait_event);
+	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+	/* reuse the packet for version range supported */
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	vstor_packet->version.major_minor =
+		storvsc_get_version(VMSTOR_CURRENT_MAJOR, VMSTOR_CURRENT_MINOR);
+
+	/*
+	 * The revision number is only used in Windows; set it to 0.
+	 */
+	vstor_packet->version.revision = 0;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->storage_channel_properties.port_number =
+					stor_device->port_number;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+	stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
+	stor_device->target_id
+		= vstor_packet->storage_channel_properties.target_id;
+
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+cleanup:
+	return ret;
+}
+
+
+static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
+{
+	struct scsi_cmnd *scmnd = cmd_request->cmd;
+	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
+	void (*scsi_done_fn)(struct scsi_cmnd *);
+	struct scsi_sense_hdr sense_hdr;
+	struct vmscsi_request *vm_srb;
+	struct storvsc_scan_work *wrk;
+	struct stor_mem_pools *memp = scmnd->device->hostdata;
+
+	vm_srb = &cmd_request->vstor_packet.vm_srb;
+	if (cmd_request->bounce_sgl_count) {
+		if (vm_srb->data_in == READ_TYPE)
+			copy_from_bounce_buffer(scsi_sglist(scmnd),
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd),
+					cmd_request->bounce_sgl_count);
+		destroy_bounce_buffer(cmd_request->bounce_sgl,
+					cmd_request->bounce_sgl_count);
+	}
+
+	/*
+	 * If there is an error; offline the device since all
+	 * error recovery strategies would have already been
+	 * deployed on the host side.
+	 */
+	if (vm_srb->srb_status == SRB_STATUS_ERROR)
+		scmnd->result = DID_TARGET_FAILURE << 16;
+	else
+		scmnd->result = vm_srb->scsi_status;
+
+	/*
+	 * If the LUN is invalid; remove the device.
+	 */
+	if (vm_srb->srb_status == SRB_STATUS_INVALID_LUN) {
+		struct storvsc_device *stor_dev;
+		struct hv_device *dev = host_dev->dev;
+		struct Scsi_Host *host;
+
+		stor_dev = get_in_stor_device(dev);
+		host = stor_dev->host;
+
+		wrk = kmalloc(sizeof(struct storvsc_scan_work),
+				GFP_ATOMIC);
+		if (!wrk) {
+			scmnd->result = DID_TARGET_FAILURE << 16;
+		} else {
+			wrk->host = host;
+			wrk->lun = vm_srb->lun;
+			INIT_WORK(&wrk->work, storvsc_remove_lun);
+			schedule_work(&wrk->work);
+		}
+	}
+
+	if (scmnd->result) {
+		if (scsi_normalize_sense(scmnd->sense_buffer,
+				SCSI_SENSE_BUFFERSIZE, &sense_hdr))
+			scsi_print_sense_hdr("storvsc", &sense_hdr);
+	}
+
+	scsi_set_resid(scmnd,
+		cmd_request->data_buffer.len -
+		vm_srb->data_transfer_length);
+
+	scsi_done_fn = scmnd->scsi_done;
+
+	scmnd->host_scribble = NULL;
+	scmnd->scsi_done = NULL;
+
+	scsi_done_fn(scmnd);
+
+	mempool_free(cmd_request, memp->request_mempool);
+}
+
+static void storvsc_on_io_completion(struct hv_device *device,
+				  struct vstor_packet *vstor_packet,
+				  struct storvsc_cmd_request *request)
+{
+	struct storvsc_device *stor_device;
+	struct vstor_packet *stor_pkt;
+
+	stor_device = hv_get_drvdata(device);
+	stor_pkt = &request->vstor_packet;
+
+	/*
+	 * The current SCSI handling on the host side does
+	 * not correctly handle:
+	 * INQUIRY command with page code parameter set to 0x80
+	 * MODE_SENSE command with cmd[2] == 0x1c
+	 *
+	 * Setup srb and scsi status so this won't be fatal.
+	 * We do this so we can distinguish truly fatal failues
+	 * (srb status == 0x4) and off-line the device in that case.
+	 */
+
+	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
+	   (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
+		vstor_packet->vm_srb.scsi_status = 0;
+		vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
+	}
+
+
+	/* Copy over the status...etc */
+	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
+	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
+	stor_pkt->vm_srb.sense_info_length =
+	vstor_packet->vm_srb.sense_info_length;
+
+	if (vstor_packet->vm_srb.scsi_status != 0 ||
+		vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS){
+		dev_warn(&device->device,
+			 "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
+			 stor_pkt->vm_srb.cdb[0],
+			 vstor_packet->vm_srb.scsi_status,
+			 vstor_packet->vm_srb.srb_status);
+	}
+
+	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
+		/* CHECK_CONDITION */
+		if (vstor_packet->vm_srb.srb_status &
+			SRB_STATUS_AUTOSENSE_VALID) {
+			/* autosense data available */
+			dev_warn(&device->device,
+				 "stor pkt %p autosense data valid - len %d\n",
+				 request,
+				 vstor_packet->vm_srb.sense_info_length);
+
+			memcpy(request->sense_buffer,
+			       vstor_packet->vm_srb.sense_data,
+			       vstor_packet->vm_srb.sense_info_length);
+
+		}
+	}
+
+	stor_pkt->vm_srb.data_transfer_length =
+	vstor_packet->vm_srb.data_transfer_length;
+
+	storvsc_command_completion(request);
+
+	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
+		stor_device->drain_notify)
+		wake_up(&stor_device->waiting_to_drain);
+
+
+}
+
+static void storvsc_on_receive(struct hv_device *device,
+			     struct vstor_packet *vstor_packet,
+			     struct storvsc_cmd_request *request)
+{
+	struct storvsc_scan_work *work;
+	struct storvsc_device *stor_device;
+
+	switch (vstor_packet->operation) {
+	case VSTOR_OPERATION_COMPLETE_IO:
+		storvsc_on_io_completion(device, vstor_packet, request);
+		break;
+
+	case VSTOR_OPERATION_REMOVE_DEVICE:
+	case VSTOR_OPERATION_ENUMERATE_BUS:
+		stor_device = get_in_stor_device(device);
+		work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
+		if (!work)
+			return;
+
+		INIT_WORK(&work->work, storvsc_bus_scan);
+		work->host = stor_device->host;
+		schedule_work(&work->work);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static void storvsc_on_channel_callback(void *context)
+{
+	struct hv_device *device = (struct hv_device *)context;
+	struct storvsc_device *stor_device;
+	u32 bytes_recvd;
+	u64 request_id;
+	unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
+	struct storvsc_cmd_request *request;
+	int ret;
+
+
+	stor_device = get_in_stor_device(device);
+	if (!stor_device)
+		return;
+
+	do {
+		ret = vmbus_recvpacket(device->channel, packet,
+				       ALIGN(sizeof(struct vstor_packet), 8),
+				       &bytes_recvd, &request_id);
+		if (ret == 0 && bytes_recvd > 0) {
+
+			request = (struct storvsc_cmd_request *)
+					(unsigned long)request_id;
+
+			if ((request == &stor_device->init_request) ||
+			    (request == &stor_device->reset_request)) {
+
+				memcpy(&request->vstor_packet, packet,
+				       sizeof(struct vstor_packet));
+				complete(&request->wait_event);
+			} else {
+				storvsc_on_receive(device,
+						(struct vstor_packet *)packet,
+						request);
+			}
+		} else {
+			break;
+		}
+	} while (1);
+
+	return;
+}
+
+static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
+{
+	struct vmstorage_channel_properties props;
+	int ret;
+
+	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
+
+	ret = vmbus_open(device->channel,
+			 ring_size,
+			 ring_size,
+			 (void *)&props,
+			 sizeof(struct vmstorage_channel_properties),
+			 storvsc_on_channel_callback, device);
+
+	if (ret != 0)
+		return ret;
+
+	ret = storvsc_channel_init(device);
+
+	return ret;
+}
+
+static int storvsc_dev_remove(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	unsigned long flags;
+
+	stor_device = hv_get_drvdata(device);
+
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	stor_device->destroy = true;
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/*
+	 * At this point, all outbound traffic should be disable. We
+	 * only allow inbound traffic (responses) to proceed so that
+	 * outstanding requests can be completed.
+	 */
+
+	storvsc_wait_to_drain(stor_device);
+
+	/*
+	 * Since we have already drained, we don't need to busy wait
+	 * as was done in final_release_stor_device()
+	 * Note that we cannot set the ext pointer to NULL until
+	 * we have drained - to drain the outgoing packets, we need to
+	 * allow incoming packets.
+	 */
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	hv_set_drvdata(device, NULL);
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/* Close the channel */
+	vmbus_close(device->channel);
+
+	kfree(stor_device);
+	return 0;
+}
+
+static int storvsc_do_io(struct hv_device *device,
+			      struct storvsc_cmd_request *request)
+{
+	struct storvsc_device *stor_device;
+	struct vstor_packet *vstor_packet;
+	int ret = 0;
+
+	vstor_packet = &request->vstor_packet;
+	stor_device = get_out_stor_device(device);
+
+	if (!stor_device)
+		return -ENODEV;
+
+
+	request->device  = device;
+
+
+	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
+
+	vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
+
+
+	vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
+
+
+	vstor_packet->vm_srb.data_transfer_length =
+	request->data_buffer.len;
+
+	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
+
+	if (request->data_buffer.len) {
+		ret = vmbus_sendpacket_multipagebuffer(device->channel,
+				&request->data_buffer,
+				vstor_packet,
+				sizeof(struct vstor_packet),
+				(unsigned long)request);
+	} else {
+		ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	}
+
+	if (ret != 0)
+		return ret;
+
+	atomic_inc(&stor_device->num_outstanding_req);
+
+	return ret;
+}
+
+static int storvsc_device_alloc(struct scsi_device *sdevice)
+{
+	struct stor_mem_pools *memp;
+	int number = STORVSC_MIN_BUF_NR;
+
+	memp = kzalloc(sizeof(struct stor_mem_pools), GFP_KERNEL);
+	if (!memp)
+		return -ENOMEM;
+
+	memp->request_pool =
+		kmem_cache_create(dev_name(&sdevice->sdev_dev),
+				sizeof(struct storvsc_cmd_request), 0,
+				SLAB_HWCACHE_ALIGN, NULL);
+
+	if (!memp->request_pool)
+		goto err0;
+
+	memp->request_mempool = mempool_create(number, mempool_alloc_slab,
+						mempool_free_slab,
+						memp->request_pool);
+
+	if (!memp->request_mempool)
+		goto err1;
+
+	sdevice->hostdata = memp;
+
+	return 0;
+
+err1:
+	kmem_cache_destroy(memp->request_pool);
+
+err0:
+	kfree(memp);
+	return -ENOMEM;
+}
+
+static void storvsc_device_destroy(struct scsi_device *sdevice)
+{
+	struct stor_mem_pools *memp = sdevice->hostdata;
+
+	mempool_destroy(memp->request_mempool);
+	kmem_cache_destroy(memp->request_pool);
+	kfree(memp);
+	sdevice->hostdata = NULL;
+}
+
+static int storvsc_device_configure(struct scsi_device *sdevice)
+{
+	scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
+				STORVSC_MAX_IO_REQUESTS);
+
+	blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
+
+	blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
+
+	return 0;
+}
+
+static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
+			   sector_t capacity, int *info)
+{
+	sector_t nsect = capacity;
+	sector_t cylinders = nsect;
+	int heads, sectors_pt;
+
+	/*
+	 * We are making up these values; let us keep it simple.
+	 */
+	heads = 0xff;
+	sectors_pt = 0x3f;      /* Sectors per track */
+	sector_div(cylinders, heads * sectors_pt);
+	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
+		cylinders = 0xffff;
+
+	info[0] = heads;
+	info[1] = sectors_pt;
+	info[2] = (int)cylinders;
+
+	return 0;
+}
+
+static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
+{
+	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
+	struct hv_device *device = host_dev->dev;
+
+	struct storvsc_device *stor_device;
+	struct storvsc_cmd_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return FAILED;
+
+	request = &stor_device->reset_request;
+	vstor_packet = &request->vstor_packet;
+
+	init_completion(&request->wait_event);
+
+	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->vm_srb.path_id = stor_device->path_id;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)&stor_device->reset_request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		return FAILED;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0)
+		return TIMEOUT_ERROR;
+
+
+	/*
+	 * At this point, all outstanding requests in the adapter
+	 * should have been flushed out and return to us
+	 */
+
+	return SUCCESS;
+}
+
+static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
+{
+	bool allowed = true;
+	u8 scsi_op = scmnd->cmnd[0];
+
+	switch (scsi_op) {
+	/*
+	 * smartd sends this command and the host does not handle
+	 * this. So, don't send it.
+	 */
+	case SET_WINDOW:
+		scmnd->result = ILLEGAL_REQUEST << 16;
+		allowed = false;
+		break;
+	default:
+		break;
+	}
+	return allowed;
+}
+
+static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
+{
+	int ret;
+	struct hv_host_device *host_dev = shost_priv(host);
+	struct hv_device *dev = host_dev->dev;
+	struct storvsc_cmd_request *cmd_request;
+	unsigned int request_size = 0;
+	int i;
+	struct scatterlist *sgl;
+	unsigned int sg_count = 0;
+	struct vmscsi_request *vm_srb;
+	struct stor_mem_pools *memp = scmnd->device->hostdata;
+
+	if (!storvsc_scsi_cmd_ok(scmnd)) {
+		scmnd->scsi_done(scmnd);
+		return 0;
+	}
+
+	request_size = sizeof(struct storvsc_cmd_request);
+
+	cmd_request = mempool_alloc(memp->request_mempool,
+				       GFP_ATOMIC);
+
+	/*
+	 * We might be invoked in an interrupt context; hence
+	 * mempool_alloc() can fail.
+	 */
+	if (!cmd_request)
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+
+	memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
+
+	/* Setup the cmd request */
+	cmd_request->cmd = scmnd;
+
+	scmnd->host_scribble = (unsigned char *)cmd_request;
+
+	vm_srb = &cmd_request->vstor_packet.vm_srb;
+
+
+	/* Build the SRB */
+	switch (scmnd->sc_data_direction) {
+	case DMA_TO_DEVICE:
+		vm_srb->data_in = WRITE_TYPE;
+		break;
+	case DMA_FROM_DEVICE:
+		vm_srb->data_in = READ_TYPE;
+		break;
+	default:
+		vm_srb->data_in = UNKNOWN_TYPE;
+		break;
+	}
+
+
+	vm_srb->port_number = host_dev->port;
+	vm_srb->path_id = scmnd->device->channel;
+	vm_srb->target_id = scmnd->device->id;
+	vm_srb->lun = scmnd->device->lun;
+
+	vm_srb->cdb_length = scmnd->cmd_len;
+
+	memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
+
+	cmd_request->sense_buffer = scmnd->sense_buffer;
+
+
+	cmd_request->data_buffer.len = scsi_bufflen(scmnd);
+	if (scsi_sg_count(scmnd)) {
+		sgl = (struct scatterlist *)scsi_sglist(scmnd);
+		sg_count = scsi_sg_count(scmnd);
+
+		/* check if we need to bounce the sgl */
+		if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
+			cmd_request->bounce_sgl =
+				create_bounce_buffer(sgl, scsi_sg_count(scmnd),
+						     scsi_bufflen(scmnd),
+						     vm_srb->data_in);
+			if (!cmd_request->bounce_sgl) {
+				ret = SCSI_MLQUEUE_HOST_BUSY;
+				goto queue_error;
+			}
+
+			cmd_request->bounce_sgl_count =
+				ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
+					PAGE_SHIFT;
+
+			if (vm_srb->data_in == WRITE_TYPE)
+				copy_to_bounce_buffer(sgl,
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd));
+
+			sgl = cmd_request->bounce_sgl;
+			sg_count = cmd_request->bounce_sgl_count;
+		}
+
+		cmd_request->data_buffer.offset = sgl[0].offset;
+
+		for (i = 0; i < sg_count; i++)
+			cmd_request->data_buffer.pfn_array[i] =
+				page_to_pfn(sg_page((&sgl[i])));
+
+	} else if (scsi_sglist(scmnd)) {
+		cmd_request->data_buffer.offset =
+			virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
+		cmd_request->data_buffer.pfn_array[0] =
+			virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
+	}
+
+	/* Invokes the vsc to start an IO */
+	ret = storvsc_do_io(dev, cmd_request);
+
+	if (ret == -EAGAIN) {
+		/* no more space */
+
+		if (cmd_request->bounce_sgl_count) {
+			destroy_bounce_buffer(cmd_request->bounce_sgl,
+					cmd_request->bounce_sgl_count);
+
+			ret = SCSI_MLQUEUE_DEVICE_BUSY;
+			goto queue_error;
+		}
+	}
+
+	return 0;
+
+queue_error:
+	mempool_free(cmd_request, memp->request_mempool);
+	scmnd->host_scribble = NULL;
+	return ret;
+}
+
+static struct scsi_host_template scsi_driver = {
+	.module	=		THIS_MODULE,
+	.name =			"storvsc_host_t",
+	.bios_param =		storvsc_get_chs,
+	.queuecommand =		storvsc_queuecommand,
+	.eh_host_reset_handler =	storvsc_host_reset_handler,
+	.slave_alloc =		storvsc_device_alloc,
+	.slave_destroy =	storvsc_device_destroy,
+	.slave_configure =	storvsc_device_configure,
+	.cmd_per_lun =		1,
+	/* 64 max_queue * 1 target */
+	.can_queue =		STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
+	.this_id =		-1,
+	/* no use setting to 0 since ll_blk_rw reset it to 1 */
+	/* currently 32 */
+	.sg_tablesize =		MAX_MULTIPAGE_BUFFER_COUNT,
+	.use_clustering =	DISABLE_CLUSTERING,
+	/* Make sure we dont get a sg segment crosses a page boundary */
+	.dma_boundary =		PAGE_SIZE-1,
+};
+
+enum {
+	SCSI_GUID,
+	IDE_GUID,
+};
+
+static const struct hv_vmbus_device_id id_table[] = {
+	/* SCSI guid */
+	{ VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
+		       0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
+	  .driver_data = SCSI_GUID },
+	/* IDE guid */
+	{ VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
+		       0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
+	  .driver_data = IDE_GUID },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(vmbus, id_table);
+
+static int storvsc_probe(struct hv_device *device,
+			const struct hv_vmbus_device_id *dev_id)
+{
+	int ret;
+	struct Scsi_Host *host;
+	struct hv_host_device *host_dev;
+	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
+	int target = 0;
+	struct storvsc_device *stor_device;
+
+	host = scsi_host_alloc(&scsi_driver,
+			       sizeof(struct hv_host_device));
+	if (!host)
+		return -ENOMEM;
+
+	host_dev = shost_priv(host);
+	memset(host_dev, 0, sizeof(struct hv_host_device));
+
+	host_dev->port = host->host_no;
+	host_dev->dev = device;
+
+
+	stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
+	if (!stor_device) {
+		ret = -ENOMEM;
+		goto err_out0;
+	}
+
+	stor_device->destroy = false;
+	init_waitqueue_head(&stor_device->waiting_to_drain);
+	stor_device->device = device;
+	stor_device->host = host;
+	hv_set_drvdata(device, stor_device);
+
+	stor_device->port_number = host->host_no;
+	ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
+	if (ret)
+		goto err_out1;
+
+	host_dev->path = stor_device->path_id;
+	host_dev->target = stor_device->target_id;
+
+	/* max # of devices per target */
+	host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
+	/* max # of targets per channel */
+	host->max_id = STORVSC_MAX_TARGETS;
+	/* max # of channels */
+	host->max_channel = STORVSC_MAX_CHANNELS - 1;
+	/* max cmd length */
+	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
+
+	/* Register the HBA and start the scsi bus scan */
+	ret = scsi_add_host(host, &device->device);
+	if (ret != 0)
+		goto err_out2;
+
+	if (!dev_is_ide) {
+		scsi_scan_host(host);
+	} else {
+		target = (device->dev_instance.b[5] << 8 |
+			 device->dev_instance.b[4]);
+		ret = scsi_add_device(host, 0, target, 0);
+		if (ret) {
+			scsi_remove_host(host);
+			goto err_out2;
+		}
+	}
+	return 0;
+
+err_out2:
+	/*
+	 * Once we have connected with the host, we would need to
+	 * to invoke storvsc_dev_remove() to rollback this state and
+	 * this call also frees up the stor_device; hence the jump around
+	 * err_out1 label.
+	 */
+	storvsc_dev_remove(device);
+	goto err_out0;
+
+err_out1:
+	kfree(stor_device);
+
+err_out0:
+	scsi_host_put(host);
+	return ret;
+}
+
+static int storvsc_remove(struct hv_device *dev)
+{
+	struct storvsc_device *stor_device = hv_get_drvdata(dev);
+	struct Scsi_Host *host = stor_device->host;
+
+	scsi_remove_host(host);
+	storvsc_dev_remove(dev);
+	scsi_host_put(host);
+
+	return 0;
+}
+
+static struct hv_driver storvsc_drv = {
+	.name = KBUILD_MODNAME,
+	.id_table = id_table,
+	.probe = storvsc_probe,
+	.remove = storvsc_remove,
+};
+
+static int __init storvsc_drv_init(void)
+{
+	u32 max_outstanding_req_per_channel;
+
+	/*
+	 * Divide the ring buffer data size (which is 1 page less
+	 * than the ring buffer size since that page is reserved for
+	 * the ring buffer indices) by the max request size (which is
+	 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
+	 */
+	max_outstanding_req_per_channel =
+		((storvsc_ringbuffer_size - PAGE_SIZE) /
+		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
+		sizeof(struct vstor_packet) + sizeof(u64),
+		sizeof(u64)));
+
+	if (max_outstanding_req_per_channel <
+	    STORVSC_MAX_IO_REQUESTS)
+		return -EINVAL;
+
+	return vmbus_driver_register(&storvsc_drv);
+}
+
+static void __exit storvsc_drv_exit(void)
+{
+	vmbus_driver_unregister(&storvsc_drv);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION(HV_DRV_VERSION);
+MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
+module_init(storvsc_drv_init);
+module_exit(storvsc_drv_exit);
-- 
1.7.4.1

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[Greg KH]

On Thu, Feb 09, 2012 at 12:04:11PM -0800, K. Y. Srinivasan wrote:
> The storage driver (storvsc_drv.c) handles all block storage devices
> assigned to Linux guests hosted on Hyper-V. This driver has been in the
> staging tree for a while and this patch moves it out of the staging area.
> As per Greg's recommendation, this patch makes no changes to the staging/hv
> directory. Once the driver moves out of staging, we will cleanup the
> staging/hv directory.
> 
> James was willing to apply this patch during the 3.3-rc phase and a decision
> was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
> patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
> I am re-sending this patch to move this driver out of staging.
> 
> 
> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> ---
>  drivers/scsi/Kconfig       |    7 +
>  drivers/scsi/Makefile      |    3 +
>  drivers/scsi/storvsc_drv.c | 1548 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1558 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/scsi/storvsc_drv.c

James, any objection to me applying this to the staging-next tree, and
at the same time, deleting this version of the driver from the
drivers/staging/hv/ directory?

thanks,

greg k-h

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1931 bytes --]



> -----Original Message-----
> From: James Bottomley [mailto:jbottomley@parallels.com]
> Sent: Wednesday, January 25, 2012 12:12 PM
> To: Greg KH
> Cc: Christoph Hellwig; KY Srinivasan; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; ohering@suse.com
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Wed, 2012-01-25 at 09:03 -0800, Greg KH wrote:
> > On Wed, Jan 25, 2012 at 03:59:26PM +0000, James Bottomley wrote:
> > > On Wed, 2012-01-25 at 07:51 -0800, Greg KH wrote:
> > > > On Wed, Jan 25, 2012 at 10:43:00AM -0500, Christoph Hellwig wrote:
> > > > > On Wed, Jan 25, 2012 at 03:29:05PM +0000, KY Srinivasan wrote:
> > > > > > James,
> > > > > > Any updates here?
> > > > >
> > > > > Given that this is a new driver without external dependencies it seems
> > > > > fine even for a 3.3 merge to me.
> > > >
> > > > Fine with me as well.
> > >
> > > OK, so what I need to linux-scsi is an applyable patch moving it out of
> > > staging.
> >
> > I think there have been about 3-4 copies of this in your email archives,
> > but if that didn't work, I'm sure that KY can create it again :)
> 
> Actually, no ... I've got a patch adding it to staging.  What I need to
> add it in -rc is the motion piece (remove from staging and add to SCSI)
> so that git doesn't say I'm trying to add 1600 lines during rc but am
> just quietly moving a file ...

Given that the final set of patches that addressed Christoph's comments were against
Greg's staging tree and the patch I sent  that moves this driver from
staging to the scsi directory is also against the staging tree, would it make sense to
take this driver through Greg's staging tree; assuming it is ok with both James and Greg. 

Regards,

K. Y

ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

> -----Original Message-----
> From: devel-bounces@linuxdriverproject.org [mailto:devel-
> bounces@linuxdriverproject.org] On Behalf Of KY Srinivasan
> Sent: Wednesday, January 25, 2012 2:23 PM
> To: James Bottomley; Greg KH
> Cc: Christoph Hellwig; devel@linuxdriverproject.org; linux-
> kernel@vger.kernel.org; ohering@suse.com
> Subject: RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> 
> 
> > -----Original Message-----
> > From: James Bottomley [mailto:jbottomley@parallels.com]
> > Sent: Wednesday, January 25, 2012 12:12 PM
> > To: Greg KH
> > Cc: Christoph Hellwig; KY Srinivasan; linux-kernel@vger.kernel.org;
> > devel@linuxdriverproject.org; ohering@suse.com
> > Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of
> the
> > staging area
> >
> > On Wed, 2012-01-25 at 09:03 -0800, Greg KH wrote:
> > > On Wed, Jan 25, 2012 at 03:59:26PM +0000, James Bottomley wrote:
> > > > On Wed, 2012-01-25 at 07:51 -0800, Greg KH wrote:
> > > > > On Wed, Jan 25, 2012 at 10:43:00AM -0500, Christoph Hellwig wrote:
> > > > > > On Wed, Jan 25, 2012 at 03:29:05PM +0000, KY Srinivasan wrote:
> > > > > > > James,
> > > > > > > Any updates here?
> > > > > >
> > > > > > Given that this is a new driver without external dependencies it seems
> > > > > > fine even for a 3.3 merge to me.
> > > > >
> > > > > Fine with me as well.
> > > >
> > > > OK, so what I need to linux-scsi is an applyable patch moving it out of
> > > > staging.
> > >
> > > I think there have been about 3-4 copies of this in your email archives,
> > > but if that didn't work, I'm sure that KY can create it again :)
> >
> > Actually, no ... I've got a patch adding it to staging.  What I need to
> > add it in -rc is the motion piece (remove from staging and add to SCSI)
> > so that git doesn't say I'm trying to add 1600 lines during rc but am
> > just quietly moving a file ...
> 
> I have sent the patch.

Let me know if  this is what you were looking for.

Regards,

K. Y
> _______________________________________________
> devel mailing list
> devel@linuxdriverproject.org
> http://driverdev.linuxdriverproject.org/mailman/listinfo/devel

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1622 bytes --]



> -----Original Message-----
> From: James Bottomley [mailto:jbottomley@parallels.com]
> Sent: Wednesday, January 25, 2012 12:12 PM
> To: Greg KH
> Cc: Christoph Hellwig; KY Srinivasan; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; ohering@suse.com
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Wed, 2012-01-25 at 09:03 -0800, Greg KH wrote:
> > On Wed, Jan 25, 2012 at 03:59:26PM +0000, James Bottomley wrote:
> > > On Wed, 2012-01-25 at 07:51 -0800, Greg KH wrote:
> > > > On Wed, Jan 25, 2012 at 10:43:00AM -0500, Christoph Hellwig wrote:
> > > > > On Wed, Jan 25, 2012 at 03:29:05PM +0000, KY Srinivasan wrote:
> > > > > > James,
> > > > > > Any updates here?
> > > > >
> > > > > Given that this is a new driver without external dependencies it seems
> > > > > fine even for a 3.3 merge to me.
> > > >
> > > > Fine with me as well.
> > >
> > > OK, so what I need to linux-scsi is an applyable patch moving it out of
> > > staging.
> >
> > I think there have been about 3-4 copies of this in your email archives,
> > but if that didn't work, I'm sure that KY can create it again :)
> 
> Actually, no ... I've got a patch adding it to staging.  What I need to
> add it in -rc is the motion piece (remove from staging and add to SCSI)
> so that git doesn't say I'm trying to add 1600 lines during rc but am
> just quietly moving a file ...

I have sent the patch.

K. Y
> 
> James

ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1636 bytes --]



> -----Original Message-----
> From: James Bottomley [mailto:jbottomley@parallels.com]
> Sent: Wednesday, January 25, 2012 12:12 PM
> To: Greg KH
> Cc: Christoph Hellwig; KY Srinivasan; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; ohering@suse.com
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Wed, 2012-01-25 at 09:03 -0800, Greg KH wrote:
> > On Wed, Jan 25, 2012 at 03:59:26PM +0000, James Bottomley wrote:
> > > On Wed, 2012-01-25 at 07:51 -0800, Greg KH wrote:
> > > > On Wed, Jan 25, 2012 at 10:43:00AM -0500, Christoph Hellwig wrote:
> > > > > On Wed, Jan 25, 2012 at 03:29:05PM +0000, KY Srinivasan wrote:
> > > > > > James,
> > > > > > Any updates here?
> > > > >
> > > > > Given that this is a new driver without external dependencies it seems
> > > > > fine even for a 3.3 merge to me.
> > > >
> > > > Fine with me as well.
> > >
> > > OK, so what I need to linux-scsi is an applyable patch moving it out of
> > > staging.
> >
> > I think there have been about 3-4 copies of this in your email archives,
> > but if that didn't work, I'm sure that KY can create it again :)
> 
> Actually, no ... I've got a patch adding it to staging.  What I need to
> add it in -rc is the motion piece (remove from staging and add to SCSI)
> so that git doesn't say I'm trying to add 1600 lines during rc but am
> just quietly moving a file ...

I will send this out soon.

Regards,

K. Y
> 
> James

ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[James Bottomley]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
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On Wed, 2012-01-25 at 09:03 -0800, Greg KH wrote:
> On Wed, Jan 25, 2012 at 03:59:26PM +0000, James Bottomley wrote:
> > On Wed, 2012-01-25 at 07:51 -0800, Greg KH wrote:
> > > On Wed, Jan 25, 2012 at 10:43:00AM -0500, Christoph Hellwig wrote:
> > > > On Wed, Jan 25, 2012 at 03:29:05PM +0000, KY Srinivasan wrote:
> > > > > James,
> > > > > Any updates here? 
> > > > 
> > > > Given that this is a new driver without external dependencies it seems
> > > > fine even for a 3.3 merge to me.
> > > 
> > > Fine with me as well.
> > 
> > OK, so what I need to linux-scsi is an applyable patch moving it out of
> > staging.
> 
> I think there have been about 3-4 copies of this in your email archives,
> but if that didn't work, I'm sure that KY can create it again :)

Actually, no ... I've got a patch adding it to staging.  What I need to
add it in -rc is the motion piece (remove from staging and add to SCSI)
so that git doesn't say I'm trying to add 1600 lines during rc but am
just quietly moving a file ...

James

ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[Greg KH]

On Wed, Jan 25, 2012 at 03:59:26PM +0000, James Bottomley wrote:
> On Wed, 2012-01-25 at 07:51 -0800, Greg KH wrote:
> > On Wed, Jan 25, 2012 at 10:43:00AM -0500, Christoph Hellwig wrote:
> > > On Wed, Jan 25, 2012 at 03:29:05PM +0000, KY Srinivasan wrote:
> > > > James,
> > > > Any updates here? 
> > > 
> > > Given that this is a new driver without external dependencies it seems
> > > fine even for a 3.3 merge to me.
> > 
> > Fine with me as well.
> 
> OK, so what I need to linux-scsi is an applyable patch moving it out of
> staging.

I think there have been about 3-4 copies of this in your email archives,
but if that didn't work, I'm sure that KY can create it again :)

thanks,

greg k-h

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[James Bottomley]

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On Wed, 2012-01-25 at 07:51 -0800, Greg KH wrote:
> On Wed, Jan 25, 2012 at 10:43:00AM -0500, Christoph Hellwig wrote:
> > On Wed, Jan 25, 2012 at 03:29:05PM +0000, KY Srinivasan wrote:
> > > James,
> > > Any updates here? 
> > 
> > Given that this is a new driver without external dependencies it seems
> > fine even for a 3.3 merge to me.
> 
> Fine with me as well.

OK, so what I need to linux-scsi is an applyable patch moving it out of
staging.

James

ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[Greg KH]

On Wed, Jan 25, 2012 at 10:43:00AM -0500, Christoph Hellwig wrote:
> On Wed, Jan 25, 2012 at 03:29:05PM +0000, KY Srinivasan wrote:
> > James,
> > Any updates here? 
> 
> Given that this is a new driver without external dependencies it seems
> fine even for a 3.3 merge to me.

Fine with me as well.

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[Christoph Hellwig]

On Wed, Jan 25, 2012 at 03:29:05PM +0000, KY Srinivasan wrote:
> James,
> Any updates here? 

Given that this is a new driver without external dependencies it seems
fine even for a 3.3 merge to me.

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

> -----Original Message-----
> From: Christoph Hellwig [mailto:hch@infradead.org]
> Sent: Monday, January 16, 2012 10:30 AM
> To: KY Srinivasan
> Cc: Christoph Hellwig; JBottomley@parallels.com; gregkh@suse.de; linux-
> kernel@vger.kernel.org; devel@linuxdriverproject.org; ohering@suse.com
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Sat, Jan 14, 2012 at 08:31:18PM +0000, KY Srinivasan wrote:
> > Thanks Christoph. Would you be taking this driver out of staging or should I ask
> Greg. James had indicated that
> > he had turned the driver over to you for reviewing.
> 
> In the end James still maintains the SCSI tree and send on all drivers.
> The only thing I can do is give a positive review.
James,
Any updates here? 

Regards,

K. Y

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

> -----Original Message-----
> From: Christoph Hellwig [mailto:hch@infradead.org]
> Sent: Monday, January 16, 2012 10:30 AM
> To: KY Srinivasan
> Cc: Christoph Hellwig; JBottomley@parallels.com; gregkh@suse.de; linux-
> kernel@vger.kernel.org; devel@linuxdriverproject.org; ohering@suse.com
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Sat, Jan 14, 2012 at 08:31:18PM +0000, KY Srinivasan wrote:
> > Thanks Christoph. Would you be taking this driver out of staging or should I ask
> Greg. James had indicated that
> > he had turned the driver over to you for reviewing.
> 
> In the end James still maintains the SCSI tree and send on all drivers.
> The only thing I can do is give a positive review.

James,

Let me know if there is something else you want me to address in this driver before it can exit staging.

Regards,

K. Y

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

Thanks Christoph.

Regards,

K. Y

> -----Original Message-----
> From: Christoph Hellwig [mailto:hch@infradead.org]
> Sent: Monday, January 16, 2012 10:30 AM
> To: KY Srinivasan
> Cc: Christoph Hellwig; JBottomley@parallels.com; gregkh@suse.de; linux-
> kernel@vger.kernel.org; devel@linuxdriverproject.org; ohering@suse.com
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Sat, Jan 14, 2012 at 08:31:18PM +0000, KY Srinivasan wrote:
> > Thanks Christoph. Would you be taking this driver out of staging or should I ask
> Greg. James had indicated that
> > he had turned the driver over to you for reviewing.
> 
> In the end James still maintains the SCSI tree and send on all drivers.
> The only thing I can do is give a positive review.

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[Christoph Hellwig]

On Sat, Jan 14, 2012 at 08:31:18PM +0000, KY Srinivasan wrote:
> Thanks Christoph. Would you be taking this driver out of staging or should I ask Greg. James had indicated that
> he had turned the driver over to you for reviewing.

In the end James still maintains the SCSI tree and send on all drivers.
The only thing I can do is give a positive review.

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

Thanks Christoph. Would you be taking this driver out of staging or should I ask Greg. James had indicated that
he had turned the driver over to you for reviewing.

Regards,

K. Y

> -----Original Message-----
> From: Christoph Hellwig [mailto:hch@infradead.org]
> Sent: Saturday, January 14, 2012 11:42 AM
> To: KY Srinivasan
> Cc: gregkh@suse.de; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; ohering@suse.com
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> The driver looks good to go to me, thanks for quickly addressing the
> comments.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[Christoph Hellwig]

The driver looks good to go to me, thanks for quickly addressing the
comments.

Reviewed-by: Christoph Hellwig <hch@lst.de>

[PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[K. Y. Srinivasan]

The storage driver (storvsc_drv.c) handles all block storage devices
assigned to Linux guests hosted on Hyper-V. This driver has been in the
staging tree for a while and this patch moves it out of the staging area.
As per Greg's recommendation, this patch makes no changes to the staging/hv
directory. Once the driver moves out of staging, we will cleanup the
staging/hv directory.

This patch includes all the patches that I have sent against the staging/hv
tree to address the comments I have gotten to date on this storage driver.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/scsi/Kconfig       |    7 +
 drivers/scsi/Makefile      |    3 +
 drivers/scsi/storvsc_drv.c | 1548 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1558 insertions(+), 0 deletions(-)
 create mode 100644 drivers/scsi/storvsc_drv.c

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 06ea3bc..4910269 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -662,6 +662,13 @@ config VMWARE_PVSCSI
 	  To compile this driver as a module, choose M here: the
 	  module will be called vmw_pvscsi.
 
+config HYPERV_STORAGE
+	tristate "Microsoft Hyper-V virtual storage driver"
+	depends on SCSI && HYPERV
+	default HYPERV
+	help
+	  Select this option to enable the Hyper-V virtual storage driver.
+
 config LIBFC
 	tristate "LibFC module"
 	select SCSI_FC_ATTRS
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 2b88749..e4c1a69 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -142,6 +142,7 @@ obj-$(CONFIG_SCSI_BNX2_ISCSI)	+= libiscsi.o bnx2i/
 obj-$(CONFIG_BE2ISCSI)		+= libiscsi.o be2iscsi/
 obj-$(CONFIG_SCSI_PMCRAID)	+= pmcraid.o
 obj-$(CONFIG_VMWARE_PVSCSI)	+= vmw_pvscsi.o
+obj-$(CONFIG_HYPERV_STORAGE)	+= hv_storvsc.o
 
 obj-$(CONFIG_ARM)		+= arm/
 
@@ -170,6 +171,8 @@ scsi_mod-$(CONFIG_SCSI_PROC_FS)	+= scsi_proc.o
 scsi_mod-y			+= scsi_trace.o
 scsi_mod-$(CONFIG_PM)		+= scsi_pm.o
 
+hv_storvsc-y			:= storvsc_drv.o
+
 scsi_tgt-y			+= scsi_tgt_lib.o scsi_tgt_if.o
 
 sd_mod-objs	:= sd.o
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
new file mode 100644
index 0000000..695ffc3
--- /dev/null
+++ b/drivers/scsi/storvsc_drv.c
@@ -0,0 +1,1548 @@
+/*
+ * Copyright (c) 2009, Microsoft Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Authors:
+ *   Haiyang Zhang <haiyangz@microsoft.com>
+ *   Hank Janssen  <hjanssen@microsoft.com>
+ *   K. Y. Srinivasan <kys@microsoft.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/hyperv.h>
+#include <linux/mempool.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_devinfo.h>
+#include <scsi/scsi_dbg.h>
+
+/*
+ * All wire protocol details (storage protocol between the guest and the host)
+ * are consolidated here.
+ *
+ * Begin protocol definitions.
+ */
+
+/*
+ * Version history:
+ * V1 Beta: 0.1
+ * V1 RC < 2008/1/31: 1.0
+ * V1 RC > 2008/1/31:  2.0
+ * Win7: 4.2
+ */
+
+#define VMSTOR_CURRENT_MAJOR  4
+#define VMSTOR_CURRENT_MINOR  2
+
+
+/*  Packet structure describing virtual storage requests. */
+enum vstor_packet_operation {
+	VSTOR_OPERATION_COMPLETE_IO		= 1,
+	VSTOR_OPERATION_REMOVE_DEVICE		= 2,
+	VSTOR_OPERATION_EXECUTE_SRB		= 3,
+	VSTOR_OPERATION_RESET_LUN		= 4,
+	VSTOR_OPERATION_RESET_ADAPTER		= 5,
+	VSTOR_OPERATION_RESET_BUS		= 6,
+	VSTOR_OPERATION_BEGIN_INITIALIZATION	= 7,
+	VSTOR_OPERATION_END_INITIALIZATION	= 8,
+	VSTOR_OPERATION_QUERY_PROTOCOL_VERSION	= 9,
+	VSTOR_OPERATION_QUERY_PROPERTIES	= 10,
+	VSTOR_OPERATION_ENUMERATE_BUS		= 11,
+	VSTOR_OPERATION_MAXIMUM			= 11
+};
+
+/*
+ * Platform neutral description of a scsi request -
+ * this remains the same across the write regardless of 32/64 bit
+ * note: it's patterned off the SCSI_PASS_THROUGH structure
+ */
+#define STORVSC_MAX_CMD_LEN			0x10
+#define STORVSC_SENSE_BUFFER_SIZE		0x12
+#define STORVSC_MAX_BUF_LEN_WITH_PADDING	0x14
+
+struct vmscsi_request {
+	u16 length;
+	u8 srb_status;
+	u8 scsi_status;
+
+	u8  port_number;
+	u8  path_id;
+	u8  target_id;
+	u8  lun;
+
+	u8  cdb_length;
+	u8  sense_info_length;
+	u8  data_in;
+	u8  reserved;
+
+	u32 data_transfer_length;
+
+	union {
+		u8 cdb[STORVSC_MAX_CMD_LEN];
+		u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
+		u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
+	};
+} __attribute((packed));
+
+
+/*
+ * This structure is sent during the intialization phase to get the different
+ * properties of the channel.
+ */
+struct vmstorage_channel_properties {
+	u16 protocol_version;
+	u8  path_id;
+	u8 target_id;
+
+	/* Note: port number is only really known on the client side */
+	u32  port_number;
+	u32  flags;
+	u32   max_transfer_bytes;
+
+	/*
+	 * This id is unique for each channel and will correspond with
+	 * vendor specific data in the inquiry data.
+	 */
+
+	u64  unique_id;
+} __packed;
+
+/*  This structure is sent during the storage protocol negotiations. */
+struct vmstorage_protocol_version {
+	/* Major (MSW) and minor (LSW) version numbers. */
+	u16 major_minor;
+
+	/*
+	 * Revision number is auto-incremented whenever this file is changed
+	 * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
+	 * definitely indicate incompatibility--but it does indicate mismatched
+	 * builds.
+	 * This is only used on the windows side. Just set it to 0.
+	 */
+	u16 revision;
+} __packed;
+
+/* Channel Property Flags */
+#define STORAGE_CHANNEL_REMOVABLE_FLAG		0x1
+#define STORAGE_CHANNEL_EMULATED_IDE_FLAG	0x2
+
+struct vstor_packet {
+	/* Requested operation type */
+	enum vstor_packet_operation operation;
+
+	/*  Flags - see below for values */
+	u32 flags;
+
+	/* Status of the request returned from the server side. */
+	u32 status;
+
+	/* Data payload area */
+	union {
+		/*
+		 * Structure used to forward SCSI commands from the
+		 * client to the server.
+		 */
+		struct vmscsi_request vm_srb;
+
+		/* Structure used to query channel properties. */
+		struct vmstorage_channel_properties storage_channel_properties;
+
+		/* Used during version negotiations. */
+		struct vmstorage_protocol_version version;
+	};
+} __packed;
+
+/*
+ * Packet Flags:
+ *
+ * This flag indicates that the server should send back a completion for this
+ * packet.
+ */
+
+#define REQUEST_COMPLETION_FLAG	0x1
+
+/* Matches Windows-end */
+enum storvsc_request_type {
+	WRITE_TYPE = 0,
+	READ_TYPE,
+	UNKNOWN_TYPE,
+};
+
+/*
+ * SRB status codes and masks; a subset of the codes used here.
+ */
+
+#define SRB_STATUS_AUTOSENSE_VALID	0x80
+#define SRB_STATUS_INVALID_LUN	0x20
+#define SRB_STATUS_SUCCESS	0x01
+#define SRB_STATUS_ERROR	0x04
+
+/*
+ * This is the end of Protocol specific defines.
+ */
+
+
+/*
+ * We setup a mempool to allocate request structures for this driver
+ * on a per-lun basis. The following define specifies the number of
+ * elements in the pool.
+ */
+
+#define STORVSC_MIN_BUF_NR				64
+static int storvsc_ringbuffer_size = (20 * PAGE_SIZE);
+
+module_param(storvsc_ringbuffer_size, int, S_IRUGO);
+MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
+
+#define STORVSC_MAX_IO_REQUESTS				128
+
+/*
+ * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
+ * reality, the path/target is not used (ie always set to 0) so our
+ * scsi host adapter essentially has 1 bus with 1 target that contains
+ * up to 256 luns.
+ */
+#define STORVSC_MAX_LUNS_PER_TARGET			64
+#define STORVSC_MAX_TARGETS				1
+#define STORVSC_MAX_CHANNELS				1
+
+
+
+struct storvsc_cmd_request {
+	struct list_head entry;
+	struct scsi_cmnd *cmd;
+
+	unsigned int bounce_sgl_count;
+	struct scatterlist *bounce_sgl;
+
+	struct hv_device *device;
+
+	/* Synchronize the request/response if needed */
+	struct completion wait_event;
+
+	unsigned char *sense_buffer;
+	struct hv_multipage_buffer data_buffer;
+	struct vstor_packet vstor_packet;
+};
+
+
+/* A storvsc device is a device object that contains a vmbus channel */
+struct storvsc_device {
+	struct hv_device *device;
+
+	bool	 destroy;
+	bool	 drain_notify;
+	atomic_t num_outstanding_req;
+	struct Scsi_Host *host;
+
+	wait_queue_head_t waiting_to_drain;
+
+	/*
+	 * Each unique Port/Path/Target represents 1 channel ie scsi
+	 * controller. In reality, the pathid, targetid is always 0
+	 * and the port is set by us
+	 */
+	unsigned int port_number;
+	unsigned char path_id;
+	unsigned char target_id;
+
+	/* Used for vsc/vsp channel reset process */
+	struct storvsc_cmd_request init_request;
+	struct storvsc_cmd_request reset_request;
+};
+
+struct stor_mem_pools {
+	struct kmem_cache *request_pool;
+	mempool_t *request_mempool;
+};
+
+struct hv_host_device {
+	struct hv_device *dev;
+	unsigned int port;
+	unsigned char path;
+	unsigned char target;
+};
+
+struct storvsc_scan_work {
+	struct work_struct work;
+	struct Scsi_Host *host;
+	uint lun;
+};
+
+static void storvsc_bus_scan(struct work_struct *work)
+{
+	struct storvsc_scan_work *wrk;
+	int id, order_id;
+
+	wrk = container_of(work, struct storvsc_scan_work, work);
+	for (id = 0; id < wrk->host->max_id; ++id) {
+		if (wrk->host->reverse_ordering)
+			order_id = wrk->host->max_id - id - 1;
+		else
+			order_id = id;
+
+		scsi_scan_target(&wrk->host->shost_gendev, 0,
+				order_id, SCAN_WILD_CARD, 1);
+	}
+	kfree(wrk);
+}
+
+static void storvsc_remove_lun(struct work_struct *work)
+{
+	struct storvsc_scan_work *wrk;
+	struct scsi_device *sdev;
+
+	wrk = container_of(work, struct storvsc_scan_work, work);
+	if (!scsi_host_get(wrk->host))
+		goto done;
+
+	sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
+
+	if (sdev) {
+		scsi_remove_device(sdev);
+		scsi_device_put(sdev);
+	}
+	scsi_host_put(wrk->host);
+
+done:
+	kfree(wrk);
+}
+
+/*
+ * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
+ * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
+ */
+
+static inline u16 storvsc_get_version(u8 major, u8 minor)
+{
+	u16 version;
+
+	version = ((major << 8) | minor);
+	return version;
+}
+
+/*
+ * We can get incoming messages from the host that are not in response to
+ * messages that we have sent out. An example of this would be messages
+ * received by the guest to notify dynamic addition/removal of LUNs. To
+ * deal with potential race conditions where the driver may be in the
+ * midst of being unloaded when we might receive an unsolicited message
+ * from the host, we have implemented a mechanism to gurantee sequential
+ * consistency:
+ *
+ * 1) Once the device is marked as being destroyed, we will fail all
+ *    outgoing messages.
+ * 2) We permit incoming messages when the device is being destroyed,
+ *    only to properly account for messages already sent out.
+ */
+
+static inline struct storvsc_device *get_out_stor_device(
+					struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+
+	stor_device = hv_get_drvdata(device);
+
+	if (stor_device && stor_device->destroy)
+		stor_device = NULL;
+
+	return stor_device;
+}
+
+
+static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
+{
+	dev->drain_notify = true;
+	wait_event(dev->waiting_to_drain,
+		   atomic_read(&dev->num_outstanding_req) == 0);
+	dev->drain_notify = false;
+}
+
+static inline struct storvsc_device *get_in_stor_device(
+					struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+
+	stor_device = hv_get_drvdata(device);
+
+	if (!stor_device)
+		goto get_in_err;
+
+	/*
+	 * If the device is being destroyed; allow incoming
+	 * traffic only to cleanup outstanding requests.
+	 */
+
+	if (stor_device->destroy  &&
+		(atomic_read(&stor_device->num_outstanding_req) == 0))
+		stor_device = NULL;
+
+get_in_err:
+	return stor_device;
+
+}
+
+static void destroy_bounce_buffer(struct scatterlist *sgl,
+				  unsigned int sg_count)
+{
+	int i;
+	struct page *page_buf;
+
+	for (i = 0; i < sg_count; i++) {
+		page_buf = sg_page((&sgl[i]));
+		if (page_buf != NULL)
+			__free_page(page_buf);
+	}
+
+	kfree(sgl);
+}
+
+static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
+{
+	int i;
+
+	/* No need to check */
+	if (sg_count < 2)
+		return -1;
+
+	/* We have at least 2 sg entries */
+	for (i = 0; i < sg_count; i++) {
+		if (i == 0) {
+			/* make sure 1st one does not have hole */
+			if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
+				return i;
+		} else if (i == sg_count - 1) {
+			/* make sure last one does not have hole */
+			if (sgl[i].offset != 0)
+				return i;
+		} else {
+			/* make sure no hole in the middle */
+			if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
+				return i;
+		}
+	}
+	return -1;
+}
+
+static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
+						unsigned int sg_count,
+						unsigned int len,
+						int write)
+{
+	int i;
+	int num_pages;
+	struct scatterlist *bounce_sgl;
+	struct page *page_buf;
+	unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
+
+	num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
+
+	bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
+	if (!bounce_sgl)
+		return NULL;
+
+	for (i = 0; i < num_pages; i++) {
+		page_buf = alloc_page(GFP_ATOMIC);
+		if (!page_buf)
+			goto cleanup;
+		sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
+	}
+
+	return bounce_sgl;
+
+cleanup:
+	destroy_bounce_buffer(bounce_sgl, num_pages);
+	return NULL;
+}
+
+/* Assume the original sgl has enough room */
+static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
+					    struct scatterlist *bounce_sgl,
+					    unsigned int orig_sgl_count,
+					    unsigned int bounce_sgl_count)
+{
+	int i;
+	int j = 0;
+	unsigned long src, dest;
+	unsigned int srclen, destlen, copylen;
+	unsigned int total_copied = 0;
+	unsigned long bounce_addr = 0;
+	unsigned long dest_addr = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for (i = 0; i < orig_sgl_count; i++) {
+		dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
+					KM_IRQ0) + orig_sgl[i].offset;
+		dest = dest_addr;
+		destlen = orig_sgl[i].length;
+
+		if (bounce_addr == 0)
+			bounce_addr =
+			(unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
+							KM_IRQ0);
+
+		while (destlen) {
+			src = bounce_addr + bounce_sgl[j].offset;
+			srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
+
+			copylen = min(srclen, destlen);
+			memcpy((void *)dest, (void *)src, copylen);
+
+			total_copied += copylen;
+			bounce_sgl[j].offset += copylen;
+			destlen -= copylen;
+			dest += copylen;
+
+			if (bounce_sgl[j].offset == bounce_sgl[j].length) {
+				/* full */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+				j++;
+
+				/*
+				 * It is possible that the number of elements
+				 * in the bounce buffer may not be equal to
+				 * the number of elements in the original
+				 * scatter list. Handle this correctly.
+				 */
+
+				if (j == bounce_sgl_count) {
+					/*
+					 * We are done; cleanup and return.
+					 */
+					kunmap_atomic((void *)(dest_addr -
+							orig_sgl[i].offset),
+							KM_IRQ0);
+					local_irq_restore(flags);
+					return total_copied;
+				}
+
+				/* if we need to use another bounce buffer */
+				if (destlen || i != orig_sgl_count - 1)
+					bounce_addr =
+					(unsigned long)kmap_atomic(
+					sg_page((&bounce_sgl[j])), KM_IRQ0);
+			} else if (destlen == 0 && i == orig_sgl_count - 1) {
+				/* unmap the last bounce that is < PAGE_SIZE */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+			}
+		}
+
+		kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
+			      KM_IRQ0);
+	}
+
+	local_irq_restore(flags);
+
+	return total_copied;
+}
+
+/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
+static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
+					  struct scatterlist *bounce_sgl,
+					  unsigned int orig_sgl_count)
+{
+	int i;
+	int j = 0;
+	unsigned long src, dest;
+	unsigned int srclen, destlen, copylen;
+	unsigned int total_copied = 0;
+	unsigned long bounce_addr = 0;
+	unsigned long src_addr = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for (i = 0; i < orig_sgl_count; i++) {
+		src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
+				KM_IRQ0) + orig_sgl[i].offset;
+		src = src_addr;
+		srclen = orig_sgl[i].length;
+
+		if (bounce_addr == 0)
+			bounce_addr =
+			(unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
+						KM_IRQ0);
+
+		while (srclen) {
+			/* assume bounce offset always == 0 */
+			dest = bounce_addr + bounce_sgl[j].length;
+			destlen = PAGE_SIZE - bounce_sgl[j].length;
+
+			copylen = min(srclen, destlen);
+			memcpy((void *)dest, (void *)src, copylen);
+
+			total_copied += copylen;
+			bounce_sgl[j].length += copylen;
+			srclen -= copylen;
+			src += copylen;
+
+			if (bounce_sgl[j].length == PAGE_SIZE) {
+				/* full..move to next entry */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+				j++;
+
+				/* if we need to use another bounce buffer */
+				if (srclen || i != orig_sgl_count - 1)
+					bounce_addr =
+					(unsigned long)kmap_atomic(
+					sg_page((&bounce_sgl[j])), KM_IRQ0);
+
+			} else if (srclen == 0 && i == orig_sgl_count - 1) {
+				/* unmap the last bounce that is < PAGE_SIZE */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+			}
+		}
+
+		kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
+	}
+
+	local_irq_restore(flags);
+
+	return total_copied;
+}
+
+static int storvsc_channel_init(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	struct storvsc_cmd_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return -ENODEV;
+
+	request = &stor_device->init_request;
+	vstor_packet = &request->vstor_packet;
+
+	/*
+	 * Now, initiate the vsc/vsp initialization protocol on the open
+	 * channel
+	 */
+	memset(request, 0, sizeof(struct storvsc_cmd_request));
+	init_completion(&request->wait_event);
+	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+	/* reuse the packet for version range supported */
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	vstor_packet->version.major_minor =
+		storvsc_get_version(VMSTOR_CURRENT_MAJOR, VMSTOR_CURRENT_MINOR);
+
+	/*
+	 * The revision number is only used in Windows; set it to 0.
+	 */
+	vstor_packet->version.revision = 0;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->storage_channel_properties.port_number =
+					stor_device->port_number;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+	stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
+	stor_device->target_id
+		= vstor_packet->storage_channel_properties.target_id;
+
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+cleanup:
+	return ret;
+}
+
+
+static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
+{
+	struct scsi_cmnd *scmnd = cmd_request->cmd;
+	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
+	void (*scsi_done_fn)(struct scsi_cmnd *);
+	struct scsi_sense_hdr sense_hdr;
+	struct vmscsi_request *vm_srb;
+	struct storvsc_scan_work *wrk;
+	struct stor_mem_pools *memp = scmnd->device->hostdata;
+
+	vm_srb = &cmd_request->vstor_packet.vm_srb;
+	if (cmd_request->bounce_sgl_count) {
+		if (vm_srb->data_in == READ_TYPE)
+			copy_from_bounce_buffer(scsi_sglist(scmnd),
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd),
+					cmd_request->bounce_sgl_count);
+		destroy_bounce_buffer(cmd_request->bounce_sgl,
+					cmd_request->bounce_sgl_count);
+	}
+
+	/*
+	 * If there is an error; offline the device since all
+	 * error recovery strategies would have already been
+	 * deployed on the host side.
+	 */
+	if (vm_srb->srb_status == SRB_STATUS_ERROR)
+		scmnd->result = DID_TARGET_FAILURE << 16;
+	else
+		scmnd->result = vm_srb->scsi_status;
+
+	/*
+	 * If the LUN is invalid; remove the device.
+	 */
+	if (vm_srb->srb_status == SRB_STATUS_INVALID_LUN) {
+		struct storvsc_device *stor_dev;
+		struct hv_device *dev = host_dev->dev;
+		struct Scsi_Host *host;
+
+		stor_dev = get_in_stor_device(dev);
+		host = stor_dev->host;
+
+		wrk = kmalloc(sizeof(struct storvsc_scan_work),
+				GFP_ATOMIC);
+		if (!wrk) {
+			scmnd->result = DID_TARGET_FAILURE << 16;
+		} else {
+			wrk->host = host;
+			wrk->lun = vm_srb->lun;
+			INIT_WORK(&wrk->work, storvsc_remove_lun);
+			schedule_work(&wrk->work);
+		}
+	}
+
+	if (scmnd->result) {
+		if (scsi_normalize_sense(scmnd->sense_buffer,
+				SCSI_SENSE_BUFFERSIZE, &sense_hdr))
+			scsi_print_sense_hdr("storvsc", &sense_hdr);
+	}
+
+	scsi_set_resid(scmnd,
+		cmd_request->data_buffer.len -
+		vm_srb->data_transfer_length);
+
+	scsi_done_fn = scmnd->scsi_done;
+
+	scmnd->host_scribble = NULL;
+	scmnd->scsi_done = NULL;
+
+	scsi_done_fn(scmnd);
+
+	mempool_free(cmd_request, memp->request_mempool);
+}
+
+static void storvsc_on_io_completion(struct hv_device *device,
+				  struct vstor_packet *vstor_packet,
+				  struct storvsc_cmd_request *request)
+{
+	struct storvsc_device *stor_device;
+	struct vstor_packet *stor_pkt;
+
+	stor_device = hv_get_drvdata(device);
+	stor_pkt = &request->vstor_packet;
+
+	/*
+	 * The current SCSI handling on the host side does
+	 * not correctly handle:
+	 * INQUIRY command with page code parameter set to 0x80
+	 * MODE_SENSE command with cmd[2] == 0x1c
+	 *
+	 * Setup srb and scsi status so this won't be fatal.
+	 * We do this so we can distinguish truly fatal failues
+	 * (srb status == 0x4) and off-line the device in that case.
+	 */
+
+	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
+	   (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
+		vstor_packet->vm_srb.scsi_status = 0;
+		vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
+	}
+
+
+	/* Copy over the status...etc */
+	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
+	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
+	stor_pkt->vm_srb.sense_info_length =
+	vstor_packet->vm_srb.sense_info_length;
+
+	if (vstor_packet->vm_srb.scsi_status != 0 ||
+		vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS){
+		dev_warn(&device->device,
+			 "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
+			 stor_pkt->vm_srb.cdb[0],
+			 vstor_packet->vm_srb.scsi_status,
+			 vstor_packet->vm_srb.srb_status);
+	}
+
+	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
+		/* CHECK_CONDITION */
+		if (vstor_packet->vm_srb.srb_status &
+			SRB_STATUS_AUTOSENSE_VALID) {
+			/* autosense data available */
+			dev_warn(&device->device,
+				 "stor pkt %p autosense data valid - len %d\n",
+				 request,
+				 vstor_packet->vm_srb.sense_info_length);
+
+			memcpy(request->sense_buffer,
+			       vstor_packet->vm_srb.sense_data,
+			       vstor_packet->vm_srb.sense_info_length);
+
+		}
+	}
+
+	stor_pkt->vm_srb.data_transfer_length =
+	vstor_packet->vm_srb.data_transfer_length;
+
+	storvsc_command_completion(request);
+
+	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
+		stor_device->drain_notify)
+		wake_up(&stor_device->waiting_to_drain);
+
+
+}
+
+static void storvsc_on_receive(struct hv_device *device,
+			     struct vstor_packet *vstor_packet,
+			     struct storvsc_cmd_request *request)
+{
+	struct storvsc_scan_work *work;
+	struct storvsc_device *stor_device;
+
+	switch (vstor_packet->operation) {
+	case VSTOR_OPERATION_COMPLETE_IO:
+		storvsc_on_io_completion(device, vstor_packet, request);
+		break;
+
+	case VSTOR_OPERATION_REMOVE_DEVICE:
+	case VSTOR_OPERATION_ENUMERATE_BUS:
+		stor_device = get_in_stor_device(device);
+		work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
+		if (!work)
+			return;
+
+		INIT_WORK(&work->work, storvsc_bus_scan);
+		work->host = stor_device->host;
+		schedule_work(&work->work);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static void storvsc_on_channel_callback(void *context)
+{
+	struct hv_device *device = (struct hv_device *)context;
+	struct storvsc_device *stor_device;
+	u32 bytes_recvd;
+	u64 request_id;
+	unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
+	struct storvsc_cmd_request *request;
+	int ret;
+
+
+	stor_device = get_in_stor_device(device);
+	if (!stor_device)
+		return;
+
+	do {
+		ret = vmbus_recvpacket(device->channel, packet,
+				       ALIGN(sizeof(struct vstor_packet), 8),
+				       &bytes_recvd, &request_id);
+		if (ret == 0 && bytes_recvd > 0) {
+
+			request = (struct storvsc_cmd_request *)
+					(unsigned long)request_id;
+
+			if ((request == &stor_device->init_request) ||
+			    (request == &stor_device->reset_request)) {
+
+				memcpy(&request->vstor_packet, packet,
+				       sizeof(struct vstor_packet));
+				complete(&request->wait_event);
+			} else {
+				storvsc_on_receive(device,
+						(struct vstor_packet *)packet,
+						request);
+			}
+		} else {
+			break;
+		}
+	} while (1);
+
+	return;
+}
+
+static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
+{
+	struct vmstorage_channel_properties props;
+	int ret;
+
+	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
+
+	ret = vmbus_open(device->channel,
+			 ring_size,
+			 ring_size,
+			 (void *)&props,
+			 sizeof(struct vmstorage_channel_properties),
+			 storvsc_on_channel_callback, device);
+
+	if (ret != 0)
+		return ret;
+
+	ret = storvsc_channel_init(device);
+
+	return ret;
+}
+
+static int storvsc_dev_remove(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	unsigned long flags;
+
+	stor_device = hv_get_drvdata(device);
+
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	stor_device->destroy = true;
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/*
+	 * At this point, all outbound traffic should be disable. We
+	 * only allow inbound traffic (responses) to proceed so that
+	 * outstanding requests can be completed.
+	 */
+
+	storvsc_wait_to_drain(stor_device);
+
+	/*
+	 * Since we have already drained, we don't need to busy wait
+	 * as was done in final_release_stor_device()
+	 * Note that we cannot set the ext pointer to NULL until
+	 * we have drained - to drain the outgoing packets, we need to
+	 * allow incoming packets.
+	 */
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	hv_set_drvdata(device, NULL);
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/* Close the channel */
+	vmbus_close(device->channel);
+
+	kfree(stor_device);
+	return 0;
+}
+
+static int storvsc_do_io(struct hv_device *device,
+			      struct storvsc_cmd_request *request)
+{
+	struct storvsc_device *stor_device;
+	struct vstor_packet *vstor_packet;
+	int ret = 0;
+
+	vstor_packet = &request->vstor_packet;
+	stor_device = get_out_stor_device(device);
+
+	if (!stor_device)
+		return -ENODEV;
+
+
+	request->device  = device;
+
+
+	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
+
+	vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
+
+
+	vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
+
+
+	vstor_packet->vm_srb.data_transfer_length =
+	request->data_buffer.len;
+
+	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
+
+	if (request->data_buffer.len) {
+		ret = vmbus_sendpacket_multipagebuffer(device->channel,
+				&request->data_buffer,
+				vstor_packet,
+				sizeof(struct vstor_packet),
+				(unsigned long)request);
+	} else {
+		ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	}
+
+	if (ret != 0)
+		return ret;
+
+	atomic_inc(&stor_device->num_outstanding_req);
+
+	return ret;
+}
+
+static int storvsc_device_alloc(struct scsi_device *sdevice)
+{
+	struct stor_mem_pools *memp;
+	int number = STORVSC_MIN_BUF_NR;
+
+	memp = kzalloc(sizeof(struct stor_mem_pools), GFP_KERNEL);
+	if (!memp)
+		return -ENOMEM;
+
+	memp->request_pool =
+		kmem_cache_create(dev_name(&sdevice->sdev_dev),
+				sizeof(struct storvsc_cmd_request), 0,
+				SLAB_HWCACHE_ALIGN, NULL);
+
+	if (!memp->request_pool)
+		goto err0;
+
+	memp->request_mempool = mempool_create(number, mempool_alloc_slab,
+						mempool_free_slab,
+						memp->request_pool);
+
+	if (!memp->request_mempool)
+		goto err1;
+
+	sdevice->hostdata = memp;
+
+	return 0;
+
+err1:
+	kmem_cache_destroy(memp->request_pool);
+
+err0:
+	kfree(memp);
+	return -ENOMEM;
+}
+
+static void storvsc_device_destroy(struct scsi_device *sdevice)
+{
+	struct stor_mem_pools *memp = sdevice->hostdata;
+
+	mempool_destroy(memp->request_mempool);
+	kmem_cache_destroy(memp->request_pool);
+	kfree(memp);
+	sdevice->hostdata = NULL;
+}
+
+static int storvsc_device_configure(struct scsi_device *sdevice)
+{
+	scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
+				STORVSC_MAX_IO_REQUESTS);
+
+	blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
+
+	blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
+
+	return 0;
+}
+
+static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
+			   sector_t capacity, int *info)
+{
+	sector_t nsect = capacity;
+	sector_t cylinders = nsect;
+	int heads, sectors_pt;
+
+	/*
+	 * We are making up these values; let us keep it simple.
+	 */
+	heads = 0xff;
+	sectors_pt = 0x3f;      /* Sectors per track */
+	sector_div(cylinders, heads * sectors_pt);
+	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
+		cylinders = 0xffff;
+
+	info[0] = heads;
+	info[1] = sectors_pt;
+	info[2] = (int)cylinders;
+
+	return 0;
+}
+
+static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
+{
+	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
+	struct hv_device *device = host_dev->dev;
+
+	struct storvsc_device *stor_device;
+	struct storvsc_cmd_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return FAILED;
+
+	request = &stor_device->reset_request;
+	vstor_packet = &request->vstor_packet;
+
+	init_completion(&request->wait_event);
+
+	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->vm_srb.path_id = stor_device->path_id;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)&stor_device->reset_request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		return FAILED;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0)
+		return TIMEOUT_ERROR;
+
+
+	/*
+	 * At this point, all outstanding requests in the adapter
+	 * should have been flushed out and return to us
+	 */
+
+	return SUCCESS;
+}
+
+static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
+{
+	bool allowed = true;
+	u8 scsi_op = scmnd->cmnd[0];
+
+	switch (scsi_op) {
+	/*
+	 * smartd sends this command and the host does not handle
+	 * this. So, don't send it.
+	 */
+	case SET_WINDOW:
+		scmnd->result = ILLEGAL_REQUEST << 16;
+		allowed = false;
+		break;
+	default:
+		break;
+	}
+	return allowed;
+}
+
+static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
+{
+	int ret;
+	struct hv_host_device *host_dev = shost_priv(host);
+	struct hv_device *dev = host_dev->dev;
+	struct storvsc_cmd_request *cmd_request;
+	unsigned int request_size = 0;
+	int i;
+	struct scatterlist *sgl;
+	unsigned int sg_count = 0;
+	struct vmscsi_request *vm_srb;
+	struct stor_mem_pools *memp = scmnd->device->hostdata;
+
+	if (!storvsc_scsi_cmd_ok(scmnd)) {
+		scmnd->scsi_done(scmnd);
+		return 0;
+	}
+
+	request_size = sizeof(struct storvsc_cmd_request);
+
+	cmd_request = mempool_alloc(memp->request_mempool,
+				       GFP_ATOMIC);
+
+	/*
+	 * We might be invoked in an interrupt context; hence
+	 * mempool_alloc() can fail.
+	 */
+	if (!cmd_request)
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+
+	memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
+
+	/* Setup the cmd request */
+	cmd_request->cmd = scmnd;
+
+	scmnd->host_scribble = (unsigned char *)cmd_request;
+
+	vm_srb = &cmd_request->vstor_packet.vm_srb;
+
+
+	/* Build the SRB */
+	switch (scmnd->sc_data_direction) {
+	case DMA_TO_DEVICE:
+		vm_srb->data_in = WRITE_TYPE;
+		break;
+	case DMA_FROM_DEVICE:
+		vm_srb->data_in = READ_TYPE;
+		break;
+	default:
+		vm_srb->data_in = UNKNOWN_TYPE;
+		break;
+	}
+
+
+	vm_srb->port_number = host_dev->port;
+	vm_srb->path_id = scmnd->device->channel;
+	vm_srb->target_id = scmnd->device->id;
+	vm_srb->lun = scmnd->device->lun;
+
+	vm_srb->cdb_length = scmnd->cmd_len;
+
+	memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
+
+	cmd_request->sense_buffer = scmnd->sense_buffer;
+
+
+	cmd_request->data_buffer.len = scsi_bufflen(scmnd);
+	if (scsi_sg_count(scmnd)) {
+		sgl = (struct scatterlist *)scsi_sglist(scmnd);
+		sg_count = scsi_sg_count(scmnd);
+
+		/* check if we need to bounce the sgl */
+		if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
+			cmd_request->bounce_sgl =
+				create_bounce_buffer(sgl, scsi_sg_count(scmnd),
+						     scsi_bufflen(scmnd),
+						     vm_srb->data_in);
+			if (!cmd_request->bounce_sgl) {
+				ret = SCSI_MLQUEUE_HOST_BUSY;
+				goto queue_error;
+			}
+
+			cmd_request->bounce_sgl_count =
+				ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
+					PAGE_SHIFT;
+
+			if (vm_srb->data_in == WRITE_TYPE)
+				copy_to_bounce_buffer(sgl,
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd));
+
+			sgl = cmd_request->bounce_sgl;
+			sg_count = cmd_request->bounce_sgl_count;
+		}
+
+		cmd_request->data_buffer.offset = sgl[0].offset;
+
+		for (i = 0; i < sg_count; i++)
+			cmd_request->data_buffer.pfn_array[i] =
+				page_to_pfn(sg_page((&sgl[i])));
+
+	} else if (scsi_sglist(scmnd)) {
+		cmd_request->data_buffer.offset =
+			virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
+		cmd_request->data_buffer.pfn_array[0] =
+			virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
+	}
+
+	/* Invokes the vsc to start an IO */
+	ret = storvsc_do_io(dev, cmd_request);
+
+	if (ret == -EAGAIN) {
+		/* no more space */
+
+		if (cmd_request->bounce_sgl_count) {
+			destroy_bounce_buffer(cmd_request->bounce_sgl,
+					cmd_request->bounce_sgl_count);
+
+			ret = SCSI_MLQUEUE_DEVICE_BUSY;
+			goto queue_error;
+		}
+	}
+
+	return 0;
+
+queue_error:
+	mempool_free(cmd_request, memp->request_mempool);
+	scmnd->host_scribble = NULL;
+	return ret;
+}
+
+static struct scsi_host_template scsi_driver = {
+	.module	=		THIS_MODULE,
+	.name =			"storvsc_host_t",
+	.bios_param =		storvsc_get_chs,
+	.queuecommand =		storvsc_queuecommand,
+	.eh_host_reset_handler =	storvsc_host_reset_handler,
+	.slave_alloc =		storvsc_device_alloc,
+	.slave_destroy =	storvsc_device_destroy,
+	.slave_configure =	storvsc_device_configure,
+	.cmd_per_lun =		1,
+	/* 64 max_queue * 1 target */
+	.can_queue =		STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
+	.this_id =		-1,
+	/* no use setting to 0 since ll_blk_rw reset it to 1 */
+	/* currently 32 */
+	.sg_tablesize =		MAX_MULTIPAGE_BUFFER_COUNT,
+	.use_clustering =	DISABLE_CLUSTERING,
+	/* Make sure we dont get a sg segment crosses a page boundary */
+	.dma_boundary =		PAGE_SIZE-1,
+};
+
+enum {
+	SCSI_GUID,
+	IDE_GUID,
+};
+
+static const struct hv_vmbus_device_id id_table[] = {
+	/* SCSI guid */
+	{ VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
+		       0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
+	  .driver_data = SCSI_GUID },
+	/* IDE guid */
+	{ VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
+		       0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
+	  .driver_data = IDE_GUID },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(vmbus, id_table);
+
+static int storvsc_probe(struct hv_device *device,
+			const struct hv_vmbus_device_id *dev_id)
+{
+	int ret;
+	struct Scsi_Host *host;
+	struct hv_host_device *host_dev;
+	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
+	int target = 0;
+	struct storvsc_device *stor_device;
+
+	host = scsi_host_alloc(&scsi_driver,
+			       sizeof(struct hv_host_device));
+	if (!host)
+		return -ENOMEM;
+
+	host_dev = shost_priv(host);
+	memset(host_dev, 0, sizeof(struct hv_host_device));
+
+	host_dev->port = host->host_no;
+	host_dev->dev = device;
+
+
+	stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
+	if (!stor_device) {
+		ret = -ENOMEM;
+		goto err_out0;
+	}
+
+	stor_device->destroy = false;
+	init_waitqueue_head(&stor_device->waiting_to_drain);
+	stor_device->device = device;
+	stor_device->host = host;
+	hv_set_drvdata(device, stor_device);
+
+	stor_device->port_number = host->host_no;
+	ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
+	if (ret)
+		goto err_out1;
+
+	host_dev->path = stor_device->path_id;
+	host_dev->target = stor_device->target_id;
+
+	/* max # of devices per target */
+	host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
+	/* max # of targets per channel */
+	host->max_id = STORVSC_MAX_TARGETS;
+	/* max # of channels */
+	host->max_channel = STORVSC_MAX_CHANNELS - 1;
+	/* max cmd length */
+	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
+
+	/* Register the HBA and start the scsi bus scan */
+	ret = scsi_add_host(host, &device->device);
+	if (ret != 0)
+		goto err_out2;
+
+	if (!dev_is_ide) {
+		scsi_scan_host(host);
+	} else {
+		target = (device->dev_instance.b[5] << 8 |
+			 device->dev_instance.b[4]);
+		ret = scsi_add_device(host, 0, target, 0);
+		if (ret) {
+			scsi_remove_host(host);
+			goto err_out2;
+		}
+	}
+	return 0;
+
+err_out2:
+	/*
+	 * Once we have connected with the host, we would need to
+	 * to invoke storvsc_dev_remove() to rollback this state and
+	 * this call also frees up the stor_device; hence the jump around
+	 * err_out1 label.
+	 */
+	storvsc_dev_remove(device);
+	goto err_out0;
+
+err_out1:
+	kfree(stor_device);
+
+err_out0:
+	scsi_host_put(host);
+	return ret;
+}
+
+static int storvsc_remove(struct hv_device *dev)
+{
+	struct storvsc_device *stor_device = hv_get_drvdata(dev);
+	struct Scsi_Host *host = stor_device->host;
+
+	scsi_remove_host(host);
+	storvsc_dev_remove(dev);
+	scsi_host_put(host);
+
+	return 0;
+}
+
+static struct hv_driver storvsc_drv = {
+	.name = KBUILD_MODNAME,
+	.id_table = id_table,
+	.probe = storvsc_probe,
+	.remove = storvsc_remove,
+};
+
+static int __init storvsc_drv_init(void)
+{
+	u32 max_outstanding_req_per_channel;
+
+	/*
+	 * Divide the ring buffer data size (which is 1 page less
+	 * than the ring buffer size since that page is reserved for
+	 * the ring buffer indices) by the max request size (which is
+	 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
+	 */
+	max_outstanding_req_per_channel =
+		((storvsc_ringbuffer_size - PAGE_SIZE) /
+		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
+		sizeof(struct vstor_packet) + sizeof(u64),
+		sizeof(u64)));
+
+	if (max_outstanding_req_per_channel <
+	    STORVSC_MAX_IO_REQUESTS)
+		return -EINVAL;
+
+	return vmbus_driver_register(&storvsc_drv);
+}
+
+static void __exit storvsc_drv_exit(void)
+{
+	vmbus_driver_unregister(&storvsc_drv);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION(HV_DRV_VERSION);
+MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
+module_init(storvsc_drv_init);
+module_exit(storvsc_drv_exit);
-- 
1.7.4.1

Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[Rolf Eike Beer]

> The storage driver (storvsc_drv.c) handles all block storage devices
> assigned to Linux guests hosted on Hyper-V. This driver has been in the
> staging tree for a while and this patch moves it out of the staging area.
> As per Greg's recommendation, this patch makes no changes to the
> staging/hv
> directory. Once the driver moves out of staging, we will cleanup the
> staging/hv directory.
>
> This patch includes all the patches that I have sent against the
> staging/hv
> tree to address the comments I have gotten to date on this storage driver.
>
> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> ---
>  drivers/scsi/Kconfig       |    7 +
>  drivers/scsi/Makefile      |    3 +
>  drivers/scsi/storvsc_drv.c | 1586
> ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1596 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/scsi/storvsc_drv.c
>
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index 06ea3bc..4910269 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -662,6 +662,13 @@ config VMWARE_PVSCSI
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called vmw_pvscsi.
>
> +config HYPERV_STORAGE
> +	tristate "Microsoft Hyper-V virtual storage driver"
> +	depends on SCSI && HYPERV
> +	default HYPERV
> +	help
> +	  Select this option to enable the Hyper-V virtual storage driver.
> +
>  config LIBFC
>  	tristate "LibFC module"
>  	select SCSI_FC_ATTRS

Maybe that help text could be slightly more verbose? Like "This is only
necessary if you plan to run this kernel as a guest on Microsoft Hyper-V"?
And I would welcome the usual "the module will be called" text for this
driver, too. See the first 2 lines of context of think hunk for a
copy&paste source of this text.

Eike

[PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[K. Y. Srinivasan]

The storage driver (storvsc_drv.c) handles all block storage devices
assigned to Linux guests hosted on Hyper-V. This driver has been in the
staging tree for a while and this patch moves it out of the staging area.
As per Greg's recommendation, this patch makes no changes to the staging/hv
directory. Once the driver moves out of staging, we will cleanup the
staging/hv directory.

This patch includes all the patches that I have sent against the staging/hv
tree to address the comments I have gotten to date on this storage driver.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/scsi/Kconfig       |    7 +
 drivers/scsi/Makefile      |    3 +
 drivers/scsi/storvsc_drv.c | 1586 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1596 insertions(+), 0 deletions(-)
 create mode 100644 drivers/scsi/storvsc_drv.c

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 06ea3bc..4910269 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -662,6 +662,13 @@ config VMWARE_PVSCSI
 	  To compile this driver as a module, choose M here: the
 	  module will be called vmw_pvscsi.
 
+config HYPERV_STORAGE
+	tristate "Microsoft Hyper-V virtual storage driver"
+	depends on SCSI && HYPERV
+	default HYPERV
+	help
+	  Select this option to enable the Hyper-V virtual storage driver.
+
 config LIBFC
 	tristate "LibFC module"
 	select SCSI_FC_ATTRS
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 2b88749..e4c1a69 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -142,6 +142,7 @@ obj-$(CONFIG_SCSI_BNX2_ISCSI)	+= libiscsi.o bnx2i/
 obj-$(CONFIG_BE2ISCSI)		+= libiscsi.o be2iscsi/
 obj-$(CONFIG_SCSI_PMCRAID)	+= pmcraid.o
 obj-$(CONFIG_VMWARE_PVSCSI)	+= vmw_pvscsi.o
+obj-$(CONFIG_HYPERV_STORAGE)	+= hv_storvsc.o
 
 obj-$(CONFIG_ARM)		+= arm/
 
@@ -170,6 +171,8 @@ scsi_mod-$(CONFIG_SCSI_PROC_FS)	+= scsi_proc.o
 scsi_mod-y			+= scsi_trace.o
 scsi_mod-$(CONFIG_PM)		+= scsi_pm.o
 
+hv_storvsc-y			:= storvsc_drv.o
+
 scsi_tgt-y			+= scsi_tgt_lib.o scsi_tgt_if.o
 
 sd_mod-objs	:= sd.o
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
new file mode 100644
index 0000000..eb853f7
--- /dev/null
+++ b/drivers/scsi/storvsc_drv.c
@@ -0,0 +1,1586 @@
+/*
+ * Copyright (c) 2009, Microsoft Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Authors:
+ *   Haiyang Zhang <haiyangz@microsoft.com>
+ *   Hank Janssen  <hjanssen@microsoft.com>
+ *   K. Y. Srinivasan <kys@microsoft.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/hyperv.h>
+#include <linux/mempool.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_devinfo.h>
+#include <scsi/scsi_dbg.h>
+
+
+#define STORVSC_MIN_BUF_NR				64
+#define STORVSC_RING_BUFFER_SIZE			(20*PAGE_SIZE)
+static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
+
+module_param(storvsc_ringbuffer_size, int, S_IRUGO);
+MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
+
+/* to alert the user that structure sizes may be mismatched even though the */
+/* protocol versions match. */
+
+
+#define REVISION_STRING(REVISION_) #REVISION_
+#define FILL_VMSTOR_REVISION(RESULT_LVALUE_)				\
+	do {								\
+		char *revision_string					\
+			= REVISION_STRING($Rev : 6 $) + 6;		\
+		RESULT_LVALUE_ = 0;					\
+		while (*revision_string >= '0'				\
+			&& *revision_string <= '9') {			\
+			RESULT_LVALUE_ *= 10;				\
+			RESULT_LVALUE_ += *revision_string - '0';	\
+			revision_string++;				\
+		}							\
+	} while (0)
+
+/* Major/minor macros.  Minor version is in LSB, meaning that earlier flat */
+/* version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1). */
+#define VMSTOR_PROTOCOL_MAJOR(VERSION_)		(((VERSION_) >> 8) & 0xff)
+#define VMSTOR_PROTOCOL_MINOR(VERSION_)		(((VERSION_))      & 0xff)
+#define VMSTOR_PROTOCOL_VERSION(MAJOR_, MINOR_)	((((MAJOR_) & 0xff) << 8) | \
+						 (((MINOR_) & 0xff)))
+#define VMSTOR_INVALID_PROTOCOL_VERSION		(-1)
+
+/* Version history: */
+/* V1 Beta                    0.1 */
+/* V1 RC < 2008/1/31          1.0 */
+/* V1 RC > 2008/1/31          2.0 */
+#define VMSTOR_PROTOCOL_VERSION_CURRENT VMSTOR_PROTOCOL_VERSION(4, 2)
+
+
+
+
+/*  This will get replaced with the max transfer length that is possible on */
+/*  the host adapter. */
+/*  The max transfer length will be published when we offer a vmbus channel. */
+#define MAX_TRANSFER_LENGTH	0x40000
+#define DEFAULT_PACKET_SIZE (sizeof(struct vmdata_gpa_direct) +	\
+			sizeof(struct vstor_packet) +		\
+			sizesizeof(u64) * (MAX_TRANSFER_LENGTH / PAGE_SIZE)))
+
+
+/*  Packet structure describing virtual storage requests. */
+enum vstor_packet_operation {
+	VSTOR_OPERATION_COMPLETE_IO		= 1,
+	VSTOR_OPERATION_REMOVE_DEVICE		= 2,
+	VSTOR_OPERATION_EXECUTE_SRB		= 3,
+	VSTOR_OPERATION_RESET_LUN		= 4,
+	VSTOR_OPERATION_RESET_ADAPTER		= 5,
+	VSTOR_OPERATION_RESET_BUS		= 6,
+	VSTOR_OPERATION_BEGIN_INITIALIZATION	= 7,
+	VSTOR_OPERATION_END_INITIALIZATION	= 8,
+	VSTOR_OPERATION_QUERY_PROTOCOL_VERSION	= 9,
+	VSTOR_OPERATION_QUERY_PROPERTIES	= 10,
+	VSTOR_OPERATION_ENUMERATE_BUS		= 11,
+	VSTOR_OPERATION_MAXIMUM			= 11
+};
+
+/*
+ * Platform neutral description of a scsi request -
+ * this remains the same across the write regardless of 32/64 bit
+ * note: it's patterned off the SCSI_PASS_THROUGH structure
+ */
+#define CDB16GENERIC_LENGTH			0x10
+
+#ifndef SENSE_BUFFER_SIZE
+#define SENSE_BUFFER_SIZE			0x12
+#endif
+
+#define MAX_DATA_BUF_LEN_WITH_PADDING		0x14
+
+struct vmscsi_request {
+	unsigned short length;
+	unsigned char srb_status;
+	unsigned char scsi_status;
+
+	unsigned char port_number;
+	unsigned char path_id;
+	unsigned char target_id;
+	unsigned char lun;
+
+	unsigned char cdb_length;
+	unsigned char sense_info_length;
+	unsigned char data_in;
+	unsigned char reserved;
+
+	unsigned int data_transfer_length;
+
+	union {
+		unsigned char cdb[CDB16GENERIC_LENGTH];
+		unsigned char sense_data[SENSE_BUFFER_SIZE];
+		unsigned char reserved_array[MAX_DATA_BUF_LEN_WITH_PADDING];
+	};
+} __attribute((packed));
+
+
+/*
+ * This structure is sent during the intialization phase to get the different
+ * properties of the channel.
+ */
+struct vmstorage_channel_properties {
+	unsigned short protocol_version;
+	unsigned char path_id;
+	unsigned char target_id;
+
+	/* Note: port number is only really known on the client side */
+	unsigned int port_number;
+	unsigned int flags;
+	unsigned int max_transfer_bytes;
+
+	/*  This id is unique for each channel and will correspond with */
+	/*  vendor specific data in the inquirydata */
+	unsigned long long unique_id;
+} __packed;
+
+/*  This structure is sent during the storage protocol negotiations. */
+struct vmstorage_protocol_version {
+	/* Major (MSW) and minor (LSW) version numbers. */
+	unsigned short major_minor;
+
+	/*
+	 * Revision number is auto-incremented whenever this file is changed
+	 * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
+	 * definitely indicate incompatibility--but it does indicate mismatched
+	 * builds.
+	 */
+	unsigned short revision;
+} __packed;
+
+/* Channel Property Flags */
+#define STORAGE_CHANNEL_REMOVABLE_FLAG		0x1
+#define STORAGE_CHANNEL_EMULATED_IDE_FLAG	0x2
+
+struct vstor_packet {
+	/* Requested operation type */
+	enum vstor_packet_operation operation;
+
+	/*  Flags - see below for values */
+	unsigned int flags;
+
+	/* Status of the request returned from the server side. */
+	unsigned int status;
+
+	/* Data payload area */
+	union {
+		/*
+		 * Structure used to forward SCSI commands from the
+		 * client to the server.
+		 */
+		struct vmscsi_request vm_srb;
+
+		/* Structure used to query channel properties. */
+		struct vmstorage_channel_properties storage_channel_properties;
+
+		/* Used during version negotiations. */
+		struct vmstorage_protocol_version version;
+	};
+} __packed;
+
+/* Packet flags */
+/*
+ * This flag indicates that the server should send back a completion for this
+ * packet.
+ */
+#define REQUEST_COMPLETION_FLAG	0x1
+
+/*  This is the set of flags that the vsc can set in any packets it sends */
+#define VSC_LEGAL_FLAGS		(REQUEST_COMPLETION_FLAG)
+
+
+/* Defines */
+
+#define STORVSC_MAX_IO_REQUESTS				128
+
+/*
+ * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
+ * reality, the path/target is not used (ie always set to 0) so our
+ * scsi host adapter essentially has 1 bus with 1 target that contains
+ * up to 256 luns.
+ */
+#define STORVSC_MAX_LUNS_PER_TARGET			64
+#define STORVSC_MAX_TARGETS				1
+#define STORVSC_MAX_CHANNELS				1
+#define STORVSC_MAX_CMD_LEN				16
+
+/* Matches Windows-end */
+enum storvsc_request_type {
+	WRITE_TYPE,
+	READ_TYPE,
+	UNKNOWN_TYPE,
+};
+
+
+struct hv_storvsc_request {
+	struct hv_device *device;
+
+	/* Synchronize the request/response if needed */
+	struct completion wait_event;
+
+	unsigned char *sense_buffer;
+	void *context;
+	void (*on_io_completion)(struct hv_storvsc_request *request);
+	struct hv_multipage_buffer data_buffer;
+
+	struct vstor_packet vstor_packet;
+};
+
+
+/* A storvsc device is a device object that contains a vmbus channel */
+struct storvsc_device {
+	struct hv_device *device;
+
+	bool	 destroy;
+	bool	 drain_notify;
+	atomic_t num_outstanding_req;
+	struct Scsi_Host *host;
+
+	wait_queue_head_t waiting_to_drain;
+
+	/*
+	 * Each unique Port/Path/Target represents 1 channel ie scsi
+	 * controller. In reality, the pathid, targetid is always 0
+	 * and the port is set by us
+	 */
+	unsigned int port_number;
+	unsigned char path_id;
+	unsigned char target_id;
+
+	/* Used for vsc/vsp channel reset process */
+	struct hv_storvsc_request init_request;
+	struct hv_storvsc_request reset_request;
+};
+
+struct stor_mem_pools {
+	struct kmem_cache *request_pool;
+	mempool_t *request_mempool;
+};
+
+struct hv_host_device {
+	struct hv_device *dev;
+	unsigned int port;
+	unsigned char path;
+	unsigned char target;
+};
+
+struct storvsc_cmd_request {
+	struct list_head entry;
+	struct scsi_cmnd *cmd;
+
+	unsigned int bounce_sgl_count;
+	struct scatterlist *bounce_sgl;
+
+	struct hv_storvsc_request request;
+};
+
+struct storvsc_scan_work {
+	struct work_struct work;
+	struct Scsi_Host *host;
+	uint lun;
+};
+
+static void storvsc_bus_scan(struct work_struct *work)
+{
+	struct storvsc_scan_work *wrk;
+	int id, order_id;
+
+	wrk = container_of(work, struct storvsc_scan_work, work);
+	for (id = 0; id < wrk->host->max_id; ++id) {
+		if (wrk->host->reverse_ordering)
+			order_id = wrk->host->max_id - id - 1;
+		else
+			order_id = id;
+
+		scsi_scan_target(&wrk->host->shost_gendev, 0,
+				order_id, SCAN_WILD_CARD, 1);
+	}
+	kfree(wrk);
+}
+
+static void storvsc_remove_lun(struct work_struct *work)
+{
+	struct storvsc_scan_work *wrk;
+	struct scsi_device *sdev;
+
+	wrk = container_of(work, struct storvsc_scan_work, work);
+	if (!scsi_host_get(wrk->host))
+		goto done;
+
+	sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
+
+	if (sdev) {
+		scsi_remove_device(sdev);
+		scsi_device_put(sdev);
+	}
+	scsi_host_put(wrk->host);
+
+done:
+	kfree(wrk);
+}
+
+static inline struct storvsc_device *get_out_stor_device(
+					struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+
+	stor_device = hv_get_drvdata(device);
+
+	if (stor_device && stor_device->destroy)
+		stor_device = NULL;
+
+	return stor_device;
+}
+
+
+static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
+{
+	dev->drain_notify = true;
+	wait_event(dev->waiting_to_drain,
+		   atomic_read(&dev->num_outstanding_req) == 0);
+	dev->drain_notify = false;
+}
+
+static inline struct storvsc_device *get_in_stor_device(
+					struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+
+	stor_device = hv_get_drvdata(device);
+
+	if (!stor_device)
+		goto get_in_err;
+
+	/*
+	 * If the device is being destroyed; allow incoming
+	 * traffic only to cleanup outstanding requests.
+	 */
+
+	if (stor_device->destroy  &&
+		(atomic_read(&stor_device->num_outstanding_req) == 0))
+		stor_device = NULL;
+
+get_in_err:
+	return stor_device;
+
+}
+
+static int storvsc_channel_init(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	struct hv_storvsc_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return -ENODEV;
+
+	request = &stor_device->init_request;
+	vstor_packet = &request->vstor_packet;
+
+	/*
+	 * Now, initiate the vsc/vsp initialization protocol on the open
+	 * channel
+	 */
+	memset(request, 0, sizeof(struct hv_storvsc_request));
+	init_completion(&request->wait_event);
+	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+	/* reuse the packet for version range supported */
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	vstor_packet->version.major_minor = VMSTOR_PROTOCOL_VERSION_CURRENT;
+	FILL_VMSTOR_REVISION(vstor_packet->version.revision);
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->storage_channel_properties.port_number =
+					stor_device->port_number;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+	stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
+	stor_device->target_id
+		= vstor_packet->storage_channel_properties.target_id;
+
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+cleanup:
+	return ret;
+}
+
+static void storvsc_on_io_completion(struct hv_device *device,
+				  struct vstor_packet *vstor_packet,
+				  struct hv_storvsc_request *request)
+{
+	struct storvsc_device *stor_device;
+	struct vstor_packet *stor_pkt;
+
+	stor_device = hv_get_drvdata(device);
+	stor_pkt = &request->vstor_packet;
+
+	/*
+	 * The current SCSI handling on the host side does
+	 * not correctly handle:
+	 * INQUIRY command with page code parameter set to 0x80
+	 * MODE_SENSE command with cmd[2] == 0x1c
+	 *
+	 * Setup srb and scsi status so this won't be fatal.
+	 * We do this so we can distinguish truly fatal failues
+	 * (srb status == 0x4) and off-line the device in that case.
+	 */
+
+	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
+		(stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
+		vstor_packet->vm_srb.scsi_status = 0;
+		vstor_packet->vm_srb.srb_status = 0x1;
+	}
+
+
+	/* Copy over the status...etc */
+	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
+	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
+	stor_pkt->vm_srb.sense_info_length =
+	vstor_packet->vm_srb.sense_info_length;
+
+	if (vstor_packet->vm_srb.scsi_status != 0 ||
+		vstor_packet->vm_srb.srb_status != 1){
+		dev_warn(&device->device,
+			 "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
+			 stor_pkt->vm_srb.cdb[0],
+			 vstor_packet->vm_srb.scsi_status,
+			 vstor_packet->vm_srb.srb_status);
+	}
+
+	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
+		/* CHECK_CONDITION */
+		if (vstor_packet->vm_srb.srb_status & 0x80) {
+			/* autosense data available */
+			dev_warn(&device->device,
+				 "stor pkt %p autosense data valid - len %d\n",
+				 request,
+				 vstor_packet->vm_srb.sense_info_length);
+
+			memcpy(request->sense_buffer,
+			       vstor_packet->vm_srb.sense_data,
+			       vstor_packet->vm_srb.sense_info_length);
+
+		}
+	}
+
+	stor_pkt->vm_srb.data_transfer_length =
+	vstor_packet->vm_srb.data_transfer_length;
+
+	request->on_io_completion(request);
+
+	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
+		stor_device->drain_notify)
+		wake_up(&stor_device->waiting_to_drain);
+
+
+}
+
+static void storvsc_on_receive(struct hv_device *device,
+			     struct vstor_packet *vstor_packet,
+			     struct hv_storvsc_request *request)
+{
+	struct storvsc_scan_work *work;
+	struct storvsc_device *stor_device;
+
+	switch (vstor_packet->operation) {
+	case VSTOR_OPERATION_COMPLETE_IO:
+		storvsc_on_io_completion(device, vstor_packet, request);
+		break;
+
+	case VSTOR_OPERATION_REMOVE_DEVICE:
+	case VSTOR_OPERATION_ENUMERATE_BUS:
+		stor_device = get_in_stor_device(device);
+		work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
+		if (!work)
+			return;
+
+		INIT_WORK(&work->work, storvsc_bus_scan);
+		work->host = stor_device->host;
+		schedule_work(&work->work);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static void storvsc_on_channel_callback(void *context)
+{
+	struct hv_device *device = (struct hv_device *)context;
+	struct storvsc_device *stor_device;
+	u32 bytes_recvd;
+	u64 request_id;
+	unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
+	struct hv_storvsc_request *request;
+	int ret;
+
+
+	stor_device = get_in_stor_device(device);
+	if (!stor_device)
+		return;
+
+	do {
+		ret = vmbus_recvpacket(device->channel, packet,
+				       ALIGN(sizeof(struct vstor_packet), 8),
+				       &bytes_recvd, &request_id);
+		if (ret == 0 && bytes_recvd > 0) {
+
+			request = (struct hv_storvsc_request *)
+					(unsigned long)request_id;
+
+			if ((request == &stor_device->init_request) ||
+			    (request == &stor_device->reset_request)) {
+
+				memcpy(&request->vstor_packet, packet,
+				       sizeof(struct vstor_packet));
+				complete(&request->wait_event);
+			} else {
+				storvsc_on_receive(device,
+						(struct vstor_packet *)packet,
+						request);
+			}
+		} else {
+			break;
+		}
+	} while (1);
+
+	return;
+}
+
+static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
+{
+	struct vmstorage_channel_properties props;
+	int ret;
+
+	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
+
+	/* Open the channel */
+	ret = vmbus_open(device->channel,
+			 ring_size,
+			 ring_size,
+			 (void *)&props,
+			 sizeof(struct vmstorage_channel_properties),
+			 storvsc_on_channel_callback, device);
+
+	if (ret != 0)
+		return ret;
+
+	ret = storvsc_channel_init(device);
+
+	return ret;
+}
+
+static int storvsc_dev_remove(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	unsigned long flags;
+
+	stor_device = hv_get_drvdata(device);
+
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	stor_device->destroy = true;
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/*
+	 * At this point, all outbound traffic should be disable. We
+	 * only allow inbound traffic (responses) to proceed so that
+	 * outstanding requests can be completed.
+	 */
+
+	storvsc_wait_to_drain(stor_device);
+
+	/*
+	 * Since we have already drained, we don't need to busy wait
+	 * as was done in final_release_stor_device()
+	 * Note that we cannot set the ext pointer to NULL until
+	 * we have drained - to drain the outgoing packets, we need to
+	 * allow incoming packets.
+	 */
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	hv_set_drvdata(device, NULL);
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/* Close the channel */
+	vmbus_close(device->channel);
+
+	kfree(stor_device);
+	return 0;
+}
+
+static int storvsc_do_io(struct hv_device *device,
+			      struct hv_storvsc_request *request)
+{
+	struct storvsc_device *stor_device;
+	struct vstor_packet *vstor_packet;
+	int ret = 0;
+
+	vstor_packet = &request->vstor_packet;
+	stor_device = get_out_stor_device(device);
+
+	if (!stor_device)
+		return -ENODEV;
+
+
+	request->device  = device;
+
+
+	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
+
+	vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
+
+
+	vstor_packet->vm_srb.sense_info_length = SENSE_BUFFER_SIZE;
+
+
+	vstor_packet->vm_srb.data_transfer_length =
+	request->data_buffer.len;
+
+	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
+
+	if (request->data_buffer.len) {
+		ret = vmbus_sendpacket_multipagebuffer(device->channel,
+				&request->data_buffer,
+				vstor_packet,
+				sizeof(struct vstor_packet),
+				(unsigned long)request);
+	} else {
+		ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	}
+
+	if (ret != 0)
+		return ret;
+
+	atomic_inc(&stor_device->num_outstanding_req);
+
+	return ret;
+}
+
+static void storvsc_get_ide_info(struct hv_device *dev, int *target, int *path)
+{
+	*target =
+		dev->dev_instance.b[5] << 8 | dev->dev_instance.b[4];
+
+	*path =
+		dev->dev_instance.b[3] << 24 |
+		dev->dev_instance.b[2] << 16 |
+		dev->dev_instance.b[1] << 8  | dev->dev_instance.b[0];
+}
+
+
+static int storvsc_device_alloc(struct scsi_device *sdevice)
+{
+	struct stor_mem_pools *memp;
+	int number = STORVSC_MIN_BUF_NR;
+
+	memp = kzalloc(sizeof(struct stor_mem_pools), GFP_KERNEL);
+	if (!memp)
+		return -ENOMEM;
+
+	memp->request_pool =
+		kmem_cache_create(dev_name(&sdevice->sdev_dev),
+				sizeof(struct storvsc_cmd_request), 0,
+				SLAB_HWCACHE_ALIGN, NULL);
+
+	if (!memp->request_pool)
+		goto err0;
+
+	memp->request_mempool = mempool_create(number, mempool_alloc_slab,
+						mempool_free_slab,
+						memp->request_pool);
+
+	if (!memp->request_mempool)
+		goto err1;
+
+	sdevice->hostdata = memp;
+
+	return 0;
+
+err1:
+	kmem_cache_destroy(memp->request_pool);
+
+err0:
+	kfree(memp);
+	return -ENOMEM;
+}
+
+static void storvsc_device_destroy(struct scsi_device *sdevice)
+{
+	struct stor_mem_pools *memp = sdevice->hostdata;
+
+	mempool_destroy(memp->request_mempool);
+	kmem_cache_destroy(memp->request_pool);
+	kfree(memp);
+	sdevice->hostdata = NULL;
+}
+
+static int storvsc_device_configure(struct scsi_device *sdevice)
+{
+	scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
+				STORVSC_MAX_IO_REQUESTS);
+
+	blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
+
+	blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
+
+	return 0;
+}
+
+static void destroy_bounce_buffer(struct scatterlist *sgl,
+				  unsigned int sg_count)
+{
+	int i;
+	struct page *page_buf;
+
+	for (i = 0; i < sg_count; i++) {
+		page_buf = sg_page((&sgl[i]));
+		if (page_buf != NULL)
+			__free_page(page_buf);
+	}
+
+	kfree(sgl);
+}
+
+static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
+{
+	int i;
+
+	/* No need to check */
+	if (sg_count < 2)
+		return -1;
+
+	/* We have at least 2 sg entries */
+	for (i = 0; i < sg_count; i++) {
+		if (i == 0) {
+			/* make sure 1st one does not have hole */
+			if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
+				return i;
+		} else if (i == sg_count - 1) {
+			/* make sure last one does not have hole */
+			if (sgl[i].offset != 0)
+				return i;
+		} else {
+			/* make sure no hole in the middle */
+			if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
+				return i;
+		}
+	}
+	return -1;
+}
+
+static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
+						unsigned int sg_count,
+						unsigned int len,
+						int write)
+{
+	int i;
+	int num_pages;
+	struct scatterlist *bounce_sgl;
+	struct page *page_buf;
+	unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
+
+	num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
+
+	bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
+	if (!bounce_sgl)
+		return NULL;
+
+	for (i = 0; i < num_pages; i++) {
+		page_buf = alloc_page(GFP_ATOMIC);
+		if (!page_buf)
+			goto cleanup;
+		sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
+	}
+
+	return bounce_sgl;
+
+cleanup:
+	destroy_bounce_buffer(bounce_sgl, num_pages);
+	return NULL;
+}
+
+
+/* Assume the original sgl has enough room */
+static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
+					    struct scatterlist *bounce_sgl,
+					    unsigned int orig_sgl_count,
+					    unsigned int bounce_sgl_count)
+{
+	int i;
+	int j = 0;
+	unsigned long src, dest;
+	unsigned int srclen, destlen, copylen;
+	unsigned int total_copied = 0;
+	unsigned long bounce_addr = 0;
+	unsigned long dest_addr = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for (i = 0; i < orig_sgl_count; i++) {
+		dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
+					KM_IRQ0) + orig_sgl[i].offset;
+		dest = dest_addr;
+		destlen = orig_sgl[i].length;
+
+		if (bounce_addr == 0)
+			bounce_addr =
+			(unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
+							KM_IRQ0);
+
+		while (destlen) {
+			src = bounce_addr + bounce_sgl[j].offset;
+			srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
+
+			copylen = min(srclen, destlen);
+			memcpy((void *)dest, (void *)src, copylen);
+
+			total_copied += copylen;
+			bounce_sgl[j].offset += copylen;
+			destlen -= copylen;
+			dest += copylen;
+
+			if (bounce_sgl[j].offset == bounce_sgl[j].length) {
+				/* full */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+				j++;
+
+				/*
+				 * It is possible that the number of elements
+				 * in the bounce buffer may not be equal to
+				 * the number of elements in the original
+				 * scatter list. Handle this correctly.
+				 */
+
+				if (j == bounce_sgl_count) {
+					/*
+					 * We are done; cleanup and return.
+					 */
+					kunmap_atomic((void *)(dest_addr -
+							orig_sgl[i].offset),
+							KM_IRQ0);
+					local_irq_restore(flags);
+					return total_copied;
+				}
+
+				/* if we need to use another bounce buffer */
+				if (destlen || i != orig_sgl_count - 1)
+					bounce_addr =
+					(unsigned long)kmap_atomic(
+					sg_page((&bounce_sgl[j])), KM_IRQ0);
+			} else if (destlen == 0 && i == orig_sgl_count - 1) {
+				/* unmap the last bounce that is < PAGE_SIZE */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+			}
+		}
+
+		kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
+			      KM_IRQ0);
+	}
+
+	local_irq_restore(flags);
+
+	return total_copied;
+}
+
+
+/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
+static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
+					  struct scatterlist *bounce_sgl,
+					  unsigned int orig_sgl_count)
+{
+	int i;
+	int j = 0;
+	unsigned long src, dest;
+	unsigned int srclen, destlen, copylen;
+	unsigned int total_copied = 0;
+	unsigned long bounce_addr = 0;
+	unsigned long src_addr = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for (i = 0; i < orig_sgl_count; i++) {
+		src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
+				KM_IRQ0) + orig_sgl[i].offset;
+		src = src_addr;
+		srclen = orig_sgl[i].length;
+
+		if (bounce_addr == 0)
+			bounce_addr =
+			(unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
+						KM_IRQ0);
+
+		while (srclen) {
+			/* assume bounce offset always == 0 */
+			dest = bounce_addr + bounce_sgl[j].length;
+			destlen = PAGE_SIZE - bounce_sgl[j].length;
+
+			copylen = min(srclen, destlen);
+			memcpy((void *)dest, (void *)src, copylen);
+
+			total_copied += copylen;
+			bounce_sgl[j].length += copylen;
+			srclen -= copylen;
+			src += copylen;
+
+			if (bounce_sgl[j].length == PAGE_SIZE) {
+				/* full..move to next entry */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+				j++;
+
+				/* if we need to use another bounce buffer */
+				if (srclen || i != orig_sgl_count - 1)
+					bounce_addr =
+					(unsigned long)kmap_atomic(
+					sg_page((&bounce_sgl[j])), KM_IRQ0);
+
+			} else if (srclen == 0 && i == orig_sgl_count - 1) {
+				/* unmap the last bounce that is < PAGE_SIZE */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+			}
+		}
+
+		kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
+	}
+
+	local_irq_restore(flags);
+
+	return total_copied;
+}
+
+
+static int storvsc_remove(struct hv_device *dev)
+{
+	struct storvsc_device *stor_device = hv_get_drvdata(dev);
+	struct Scsi_Host *host = stor_device->host;
+
+	scsi_remove_host(host);
+
+	scsi_host_put(host);
+
+	storvsc_dev_remove(dev);
+
+	return 0;
+}
+
+
+static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
+			   sector_t capacity, int *info)
+{
+	sector_t nsect = capacity;
+	sector_t cylinders = nsect;
+	int heads, sectors_pt;
+
+	/*
+	 * We are making up these values; let us keep it simple.
+	 */
+	heads = 0xff;
+	sectors_pt = 0x3f;      /* Sectors per track */
+	sector_div(cylinders, heads * sectors_pt);
+	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
+		cylinders = 0xffff;
+
+	info[0] = heads;
+	info[1] = sectors_pt;
+	info[2] = (int)cylinders;
+
+	return 0;
+}
+
+static int storvsc_host_reset(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	struct hv_storvsc_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return FAILED;
+
+	request = &stor_device->reset_request;
+	vstor_packet = &request->vstor_packet;
+
+	init_completion(&request->wait_event);
+
+	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->vm_srb.path_id = stor_device->path_id;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)&stor_device->reset_request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		return FAILED;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0)
+		return TIMEOUT_ERROR;
+
+
+	/*
+	 * At this point, all outstanding requests in the adapter
+	 * should have been flushed out and return to us
+	 */
+
+	return SUCCESS;
+}
+
+
+/*
+ * storvsc_host_reset_handler - Reset the scsi HBA
+ */
+static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
+{
+	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
+	struct hv_device *dev = host_dev->dev;
+
+	return storvsc_host_reset(dev);
+}
+
+
+/*
+ * storvsc_command_completion - Command completion processing
+ */
+static void storvsc_command_completion(struct hv_storvsc_request *request)
+{
+	struct storvsc_cmd_request *cmd_request =
+		(struct storvsc_cmd_request *)request->context;
+	struct scsi_cmnd *scmnd = cmd_request->cmd;
+	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
+	void (*scsi_done_fn)(struct scsi_cmnd *);
+	struct scsi_sense_hdr sense_hdr;
+	struct vmscsi_request *vm_srb;
+	struct storvsc_scan_work *wrk;
+	struct stor_mem_pools *memp = scmnd->device->hostdata;
+
+	vm_srb = &request->vstor_packet.vm_srb;
+	if (cmd_request->bounce_sgl_count) {
+		if (vm_srb->data_in == READ_TYPE)
+			copy_from_bounce_buffer(scsi_sglist(scmnd),
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd),
+					cmd_request->bounce_sgl_count);
+		destroy_bounce_buffer(cmd_request->bounce_sgl,
+					cmd_request->bounce_sgl_count);
+	}
+
+	/*
+	 * If there is an error; offline the device since all
+	 * error recovery strategies would have already been
+	 * deployed on the host side.
+	 */
+	if (vm_srb->srb_status == 0x4)
+		scmnd->result = DID_TARGET_FAILURE << 16;
+	else
+		scmnd->result = vm_srb->scsi_status;
+
+	/*
+	 * If the LUN is invalid; remove the device.
+	 */
+	if (vm_srb->srb_status == 0x20) {
+		struct storvsc_device *stor_dev;
+		struct hv_device *dev = host_dev->dev;
+		struct Scsi_Host *host;
+
+		stor_dev = get_in_stor_device(dev);
+		host = stor_dev->host;
+
+		wrk = kmalloc(sizeof(struct storvsc_scan_work),
+				GFP_ATOMIC);
+		if (!wrk) {
+			scmnd->result = DID_TARGET_FAILURE << 16;
+		} else {
+			wrk->host = host;
+			wrk->lun = vm_srb->lun;
+			INIT_WORK(&wrk->work, storvsc_remove_lun);
+			schedule_work(&wrk->work);
+		}
+	}
+
+	if (scmnd->result) {
+		if (scsi_normalize_sense(scmnd->sense_buffer,
+				SCSI_SENSE_BUFFERSIZE, &sense_hdr))
+			scsi_print_sense_hdr("storvsc", &sense_hdr);
+	}
+
+	scsi_set_resid(scmnd,
+		request->data_buffer.len -
+		vm_srb->data_transfer_length);
+
+	scsi_done_fn = scmnd->scsi_done;
+
+	scmnd->host_scribble = NULL;
+	scmnd->scsi_done = NULL;
+
+	scsi_done_fn(scmnd);
+
+	mempool_free(cmd_request, memp->request_mempool);
+}
+
+static bool storvsc_check_scsi_cmd(struct scsi_cmnd *scmnd)
+{
+	bool allowed = true;
+	u8 scsi_op = scmnd->cmnd[0];
+
+	switch (scsi_op) {
+	/* smartd sends this command, which will offline the device */
+	case SET_WINDOW:
+		scmnd->result = ILLEGAL_REQUEST << 16;
+		allowed = false;
+		break;
+	default:
+		break;
+	}
+	return allowed;
+}
+
+/*
+ * storvsc_queuecommand - Initiate command processing
+ */
+static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
+{
+	int ret;
+	struct hv_host_device *host_dev = shost_priv(host);
+	struct hv_device *dev = host_dev->dev;
+	struct hv_storvsc_request *request;
+	struct storvsc_cmd_request *cmd_request;
+	unsigned int request_size = 0;
+	int i;
+	struct scatterlist *sgl;
+	unsigned int sg_count = 0;
+	struct vmscsi_request *vm_srb;
+	struct stor_mem_pools *memp = scmnd->device->hostdata;
+
+	if (storvsc_check_scsi_cmd(scmnd) == false) {
+		scmnd->scsi_done(scmnd);
+		return 0;
+	}
+
+	/* If retrying, no need to prep the cmd */
+	if (scmnd->host_scribble) {
+
+		cmd_request =
+			(struct storvsc_cmd_request *)scmnd->host_scribble;
+
+		goto retry_request;
+	}
+
+	request_size = sizeof(struct storvsc_cmd_request);
+
+	cmd_request = mempool_alloc(memp->request_mempool,
+				       GFP_ATOMIC);
+	if (!cmd_request)
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+
+	memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
+
+	/* Setup the cmd request */
+	cmd_request->bounce_sgl_count = 0;
+	cmd_request->bounce_sgl = NULL;
+	cmd_request->cmd = scmnd;
+
+	scmnd->host_scribble = (unsigned char *)cmd_request;
+
+	request = &cmd_request->request;
+	vm_srb = &request->vstor_packet.vm_srb;
+
+
+	/* Build the SRB */
+	switch (scmnd->sc_data_direction) {
+	case DMA_TO_DEVICE:
+		vm_srb->data_in = WRITE_TYPE;
+		break;
+	case DMA_FROM_DEVICE:
+		vm_srb->data_in = READ_TYPE;
+		break;
+	default:
+		vm_srb->data_in = UNKNOWN_TYPE;
+		break;
+	}
+
+	request->on_io_completion = storvsc_command_completion;
+	request->context = cmd_request;/* scmnd; */
+
+	vm_srb->port_number = host_dev->port;
+	vm_srb->path_id = scmnd->device->channel;
+	vm_srb->target_id = scmnd->device->id;
+	vm_srb->lun = scmnd->device->lun;
+
+	vm_srb->cdb_length = scmnd->cmd_len;
+
+	memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
+
+	request->sense_buffer = scmnd->sense_buffer;
+
+
+	request->data_buffer.len = scsi_bufflen(scmnd);
+	if (scsi_sg_count(scmnd)) {
+		sgl = (struct scatterlist *)scsi_sglist(scmnd);
+		sg_count = scsi_sg_count(scmnd);
+
+		/* check if we need to bounce the sgl */
+		if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
+			cmd_request->bounce_sgl =
+				create_bounce_buffer(sgl, scsi_sg_count(scmnd),
+						     scsi_bufflen(scmnd),
+						     vm_srb->data_in);
+			if (!cmd_request->bounce_sgl) {
+				scmnd->host_scribble = NULL;
+				mempool_free(cmd_request,
+						memp->request_mempool);
+
+				return SCSI_MLQUEUE_HOST_BUSY;
+			}
+
+			cmd_request->bounce_sgl_count =
+				ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
+					PAGE_SHIFT;
+
+			if (vm_srb->data_in == WRITE_TYPE)
+				copy_to_bounce_buffer(sgl,
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd));
+
+			sgl = cmd_request->bounce_sgl;
+			sg_count = cmd_request->bounce_sgl_count;
+		}
+
+		request->data_buffer.offset = sgl[0].offset;
+
+		for (i = 0; i < sg_count; i++)
+			request->data_buffer.pfn_array[i] =
+				page_to_pfn(sg_page((&sgl[i])));
+
+	} else if (scsi_sglist(scmnd)) {
+		request->data_buffer.offset =
+			virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
+		request->data_buffer.pfn_array[0] =
+			virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
+	}
+
+retry_request:
+	/* Invokes the vsc to start an IO */
+	ret = storvsc_do_io(dev, &cmd_request->request);
+
+	if (ret == -EAGAIN) {
+		/* no more space */
+
+		if (cmd_request->bounce_sgl_count)
+			destroy_bounce_buffer(cmd_request->bounce_sgl,
+					cmd_request->bounce_sgl_count);
+
+		mempool_free(cmd_request, memp->request_mempool);
+
+		scmnd->host_scribble = NULL;
+
+		ret = SCSI_MLQUEUE_DEVICE_BUSY;
+	}
+
+	return ret;
+}
+
+/* Scsi driver */
+static struct scsi_host_template scsi_driver = {
+	.module	=		THIS_MODULE,
+	.name =			"storvsc_host_t",
+	.bios_param =		storvsc_get_chs,
+	.queuecommand =		storvsc_queuecommand,
+	.eh_host_reset_handler =	storvsc_host_reset_handler,
+	.slave_alloc =		storvsc_device_alloc,
+	.slave_destroy =	storvsc_device_destroy,
+	.slave_configure =	storvsc_device_configure,
+	.cmd_per_lun =		1,
+	/* 64 max_queue * 1 target */
+	.can_queue =		STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
+	.this_id =		-1,
+	/* no use setting to 0 since ll_blk_rw reset it to 1 */
+	/* currently 32 */
+	.sg_tablesize =		MAX_MULTIPAGE_BUFFER_COUNT,
+	.use_clustering =	DISABLE_CLUSTERING,
+	/* Make sure we dont get a sg segment crosses a page boundary */
+	.dma_boundary =		PAGE_SIZE-1,
+};
+
+enum {
+	SCSI_GUID,
+	IDE_GUID,
+};
+
+static const struct hv_vmbus_device_id id_table[] = {
+	/* SCSI guid */
+	{ VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
+		       0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
+	  .driver_data = SCSI_GUID },
+	/* IDE guid */
+	{ VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
+		       0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
+	  .driver_data = IDE_GUID },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(vmbus, id_table);
+
+
+/*
+ * storvsc_probe - Add a new device for this driver
+ */
+
+static int storvsc_probe(struct hv_device *device,
+			const struct hv_vmbus_device_id *dev_id)
+{
+	int ret;
+	struct Scsi_Host *host;
+	struct hv_host_device *host_dev;
+	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
+	int path = 0;
+	int target = 0;
+	struct storvsc_device *stor_device;
+
+	host = scsi_host_alloc(&scsi_driver,
+			       sizeof(struct hv_host_device));
+	if (!host)
+		return -ENOMEM;
+
+	host_dev = shost_priv(host);
+	memset(host_dev, 0, sizeof(struct hv_host_device));
+
+	host_dev->port = host->host_no;
+	host_dev->dev = device;
+
+
+	stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
+	if (!stor_device) {
+		ret = -ENOMEM;
+		goto err_out0;
+	}
+
+	stor_device->destroy = false;
+	init_waitqueue_head(&stor_device->waiting_to_drain);
+	stor_device->device = device;
+	stor_device->host = host;
+	hv_set_drvdata(device, stor_device);
+
+	stor_device->port_number = host->host_no;
+	ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
+	if (ret)
+		goto err_out1;
+
+	if (dev_is_ide)
+		storvsc_get_ide_info(device, &target, &path);
+
+	host_dev->path = stor_device->path_id;
+	host_dev->target = stor_device->target_id;
+
+	/* max # of devices per target */
+	host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
+	/* max # of targets per channel */
+	host->max_id = STORVSC_MAX_TARGETS;
+	/* max # of channels */
+	host->max_channel = STORVSC_MAX_CHANNELS - 1;
+	/* max cmd length */
+	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
+
+	/* Register the HBA and start the scsi bus scan */
+	ret = scsi_add_host(host, &device->device);
+	if (ret != 0)
+		goto err_out2;
+
+	if (!dev_is_ide) {
+		scsi_scan_host(host);
+		return 0;
+	}
+	ret = scsi_add_device(host, 0, target, 0);
+	if (ret) {
+		scsi_remove_host(host);
+		goto err_out2;
+	}
+	return 0;
+
+err_out2:
+	/*
+	 * Once we have connected with the host, we would need to
+	 * to invoke storvsc_dev_remove() to rollback this state and
+	 * this call also frees up the stor_device; hence the jump around
+	 * err_out1 label.
+	 */
+	storvsc_dev_remove(device);
+	goto err_out0;
+
+err_out1:
+	kfree(stor_device);
+
+err_out0:
+	scsi_host_put(host);
+	return ret;
+}
+
+/* The one and only one */
+
+static struct hv_driver storvsc_drv = {
+	.name = KBUILD_MODNAME,
+	.id_table = id_table,
+	.probe = storvsc_probe,
+	.remove = storvsc_remove,
+};
+
+static int __init storvsc_drv_init(void)
+{
+	u32 max_outstanding_req_per_channel;
+
+	/*
+	 * Divide the ring buffer data size (which is 1 page less
+	 * than the ring buffer size since that page is reserved for
+	 * the ring buffer indices) by the max request size (which is
+	 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
+	 */
+	max_outstanding_req_per_channel =
+		((storvsc_ringbuffer_size - PAGE_SIZE) /
+		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
+		sizeof(struct vstor_packet) + sizeof(u64),
+		sizeof(u64)));
+
+	if (max_outstanding_req_per_channel <
+	    STORVSC_MAX_IO_REQUESTS)
+		return -EINVAL;
+
+	return vmbus_driver_register(&storvsc_drv);
+}
+
+static void __exit storvsc_drv_exit(void)
+{
+	vmbus_driver_unregister(&storvsc_drv);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION(HV_DRV_VERSION);
+MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
+module_init(storvsc_drv_init);
+module_exit(storvsc_drv_exit);
-- 
1.7.4.1

[PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[K. Y. Srinivasan]

The storage driver (storvsc_drv.c) handles all block storage devices
assigned to Linux guests hosted on Hyper-V. This driver has been in the
staging tree for a while and this patch moves it out of the staging area.
As per Greg's recommendation, this patch makes no changes to the staging/hv
directory. Once the driver moves out of staging, we will cleanup the
staging/hv directory.

This patch includes all the patches that I have sent against the staging/hv
tree to address the comments I have gotten to date on this storage driver.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/scsi/Kconfig       |    7 +
 drivers/scsi/Makefile      |    3 +
 drivers/scsi/storvsc_drv.c | 1583 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1593 insertions(+), 0 deletions(-)
 create mode 100644 drivers/scsi/storvsc_drv.c

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 06ea3bc..4910269 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -662,6 +662,13 @@ config VMWARE_PVSCSI
 	  To compile this driver as a module, choose M here: the
 	  module will be called vmw_pvscsi.
 
+config HYPERV_STORAGE
+	tristate "Microsoft Hyper-V virtual storage driver"
+	depends on SCSI && HYPERV
+	default HYPERV
+	help
+	  Select this option to enable the Hyper-V virtual storage driver.
+
 config LIBFC
 	tristate "LibFC module"
 	select SCSI_FC_ATTRS
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 2b88749..e4c1a69 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -142,6 +142,7 @@ obj-$(CONFIG_SCSI_BNX2_ISCSI)	+= libiscsi.o bnx2i/
 obj-$(CONFIG_BE2ISCSI)		+= libiscsi.o be2iscsi/
 obj-$(CONFIG_SCSI_PMCRAID)	+= pmcraid.o
 obj-$(CONFIG_VMWARE_PVSCSI)	+= vmw_pvscsi.o
+obj-$(CONFIG_HYPERV_STORAGE)	+= hv_storvsc.o
 
 obj-$(CONFIG_ARM)		+= arm/
 
@@ -170,6 +171,8 @@ scsi_mod-$(CONFIG_SCSI_PROC_FS)	+= scsi_proc.o
 scsi_mod-y			+= scsi_trace.o
 scsi_mod-$(CONFIG_PM)		+= scsi_pm.o
 
+hv_storvsc-y			:= storvsc_drv.o
+
 scsi_tgt-y			+= scsi_tgt_lib.o scsi_tgt_if.o
 
 sd_mod-objs	:= sd.o
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
new file mode 100644
index 0000000..18f8771
--- /dev/null
+++ b/drivers/scsi/storvsc_drv.c
@@ -0,0 +1,1583 @@
+/*
+ * Copyright (c) 2009, Microsoft Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Authors:
+ *   Haiyang Zhang <haiyangz@microsoft.com>
+ *   Hank Janssen  <hjanssen@microsoft.com>
+ *   K. Y. Srinivasan <kys@microsoft.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/hyperv.h>
+#include <linux/mempool.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_devinfo.h>
+#include <scsi/scsi_dbg.h>
+
+
+#define STORVSC_MIN_BUF_NR				64
+#define STORVSC_RING_BUFFER_SIZE			(20*PAGE_SIZE)
+static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
+
+module_param(storvsc_ringbuffer_size, int, S_IRUGO);
+MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
+
+/* to alert the user that structure sizes may be mismatched even though the */
+/* protocol versions match. */
+
+
+#define REVISION_STRING(REVISION_) #REVISION_
+#define FILL_VMSTOR_REVISION(RESULT_LVALUE_)				\
+	do {								\
+		char *revision_string					\
+			= REVISION_STRING($Rev : 6 $) + 6;		\
+		RESULT_LVALUE_ = 0;					\
+		while (*revision_string >= '0'				\
+			&& *revision_string <= '9') {			\
+			RESULT_LVALUE_ *= 10;				\
+			RESULT_LVALUE_ += *revision_string - '0';	\
+			revision_string++;				\
+		}							\
+	} while (0)
+
+/* Major/minor macros.  Minor version is in LSB, meaning that earlier flat */
+/* version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1). */
+#define VMSTOR_PROTOCOL_MAJOR(VERSION_)		(((VERSION_) >> 8) & 0xff)
+#define VMSTOR_PROTOCOL_MINOR(VERSION_)		(((VERSION_))      & 0xff)
+#define VMSTOR_PROTOCOL_VERSION(MAJOR_, MINOR_)	((((MAJOR_) & 0xff) << 8) | \
+						 (((MINOR_) & 0xff)))
+#define VMSTOR_INVALID_PROTOCOL_VERSION		(-1)
+
+/* Version history: */
+/* V1 Beta                    0.1 */
+/* V1 RC < 2008/1/31          1.0 */
+/* V1 RC > 2008/1/31          2.0 */
+#define VMSTOR_PROTOCOL_VERSION_CURRENT VMSTOR_PROTOCOL_VERSION(4, 2)
+
+
+
+
+/*  This will get replaced with the max transfer length that is possible on */
+/*  the host adapter. */
+/*  The max transfer length will be published when we offer a vmbus channel. */
+#define MAX_TRANSFER_LENGTH	0x40000
+#define DEFAULT_PACKET_SIZE (sizeof(struct vmdata_gpa_direct) +	\
+			sizeof(struct vstor_packet) +		\
+			sizesizeof(u64) * (MAX_TRANSFER_LENGTH / PAGE_SIZE)))
+
+
+/*  Packet structure describing virtual storage requests. */
+enum vstor_packet_operation {
+	VSTOR_OPERATION_COMPLETE_IO		= 1,
+	VSTOR_OPERATION_REMOVE_DEVICE		= 2,
+	VSTOR_OPERATION_EXECUTE_SRB		= 3,
+	VSTOR_OPERATION_RESET_LUN		= 4,
+	VSTOR_OPERATION_RESET_ADAPTER		= 5,
+	VSTOR_OPERATION_RESET_BUS		= 6,
+	VSTOR_OPERATION_BEGIN_INITIALIZATION	= 7,
+	VSTOR_OPERATION_END_INITIALIZATION	= 8,
+	VSTOR_OPERATION_QUERY_PROTOCOL_VERSION	= 9,
+	VSTOR_OPERATION_QUERY_PROPERTIES	= 10,
+	VSTOR_OPERATION_ENUMERATE_BUS		= 11,
+	VSTOR_OPERATION_MAXIMUM			= 11
+};
+
+/*
+ * Platform neutral description of a scsi request -
+ * this remains the same across the write regardless of 32/64 bit
+ * note: it's patterned off the SCSI_PASS_THROUGH structure
+ */
+#define CDB16GENERIC_LENGTH			0x10
+
+#ifndef SENSE_BUFFER_SIZE
+#define SENSE_BUFFER_SIZE			0x12
+#endif
+
+#define MAX_DATA_BUF_LEN_WITH_PADDING		0x14
+
+struct vmscsi_request {
+	unsigned short length;
+	unsigned char srb_status;
+	unsigned char scsi_status;
+
+	unsigned char port_number;
+	unsigned char path_id;
+	unsigned char target_id;
+	unsigned char lun;
+
+	unsigned char cdb_length;
+	unsigned char sense_info_length;
+	unsigned char data_in;
+	unsigned char reserved;
+
+	unsigned int data_transfer_length;
+
+	union {
+		unsigned char cdb[CDB16GENERIC_LENGTH];
+		unsigned char sense_data[SENSE_BUFFER_SIZE];
+		unsigned char reserved_array[MAX_DATA_BUF_LEN_WITH_PADDING];
+	};
+} __attribute((packed));
+
+
+/*
+ * This structure is sent during the intialization phase to get the different
+ * properties of the channel.
+ */
+struct vmstorage_channel_properties {
+	unsigned short protocol_version;
+	unsigned char path_id;
+	unsigned char target_id;
+
+	/* Note: port number is only really known on the client side */
+	unsigned int port_number;
+	unsigned int flags;
+	unsigned int max_transfer_bytes;
+
+	/*  This id is unique for each channel and will correspond with */
+	/*  vendor specific data in the inquirydata */
+	unsigned long long unique_id;
+} __packed;
+
+/*  This structure is sent during the storage protocol negotiations. */
+struct vmstorage_protocol_version {
+	/* Major (MSW) and minor (LSW) version numbers. */
+	unsigned short major_minor;
+
+	/*
+	 * Revision number is auto-incremented whenever this file is changed
+	 * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
+	 * definitely indicate incompatibility--but it does indicate mismatched
+	 * builds.
+	 */
+	unsigned short revision;
+} __packed;
+
+/* Channel Property Flags */
+#define STORAGE_CHANNEL_REMOVABLE_FLAG		0x1
+#define STORAGE_CHANNEL_EMULATED_IDE_FLAG	0x2
+
+struct vstor_packet {
+	/* Requested operation type */
+	enum vstor_packet_operation operation;
+
+	/*  Flags - see below for values */
+	unsigned int flags;
+
+	/* Status of the request returned from the server side. */
+	unsigned int status;
+
+	/* Data payload area */
+	union {
+		/*
+		 * Structure used to forward SCSI commands from the
+		 * client to the server.
+		 */
+		struct vmscsi_request vm_srb;
+
+		/* Structure used to query channel properties. */
+		struct vmstorage_channel_properties storage_channel_properties;
+
+		/* Used during version negotiations. */
+		struct vmstorage_protocol_version version;
+	};
+} __packed;
+
+/* Packet flags */
+/*
+ * This flag indicates that the server should send back a completion for this
+ * packet.
+ */
+#define REQUEST_COMPLETION_FLAG	0x1
+
+/*  This is the set of flags that the vsc can set in any packets it sends */
+#define VSC_LEGAL_FLAGS		(REQUEST_COMPLETION_FLAG)
+
+
+/* Defines */
+
+#define STORVSC_MAX_IO_REQUESTS				128
+
+/*
+ * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
+ * reality, the path/target is not used (ie always set to 0) so our
+ * scsi host adapter essentially has 1 bus with 1 target that contains
+ * up to 256 luns.
+ */
+#define STORVSC_MAX_LUNS_PER_TARGET			64
+#define STORVSC_MAX_TARGETS				1
+#define STORVSC_MAX_CHANNELS				1
+#define STORVSC_MAX_CMD_LEN				16
+
+/* Matches Windows-end */
+enum storvsc_request_type {
+	WRITE_TYPE,
+	READ_TYPE,
+	UNKNOWN_TYPE,
+};
+
+
+struct hv_storvsc_request {
+	struct hv_device *device;
+
+	/* Synchronize the request/response if needed */
+	struct completion wait_event;
+
+	unsigned char *sense_buffer;
+	void *context;
+	void (*on_io_completion)(struct hv_storvsc_request *request);
+	struct hv_multipage_buffer data_buffer;
+
+	struct vstor_packet vstor_packet;
+};
+
+
+/* A storvsc device is a device object that contains a vmbus channel */
+struct storvsc_device {
+	struct hv_device *device;
+
+	bool	 destroy;
+	bool	 drain_notify;
+	atomic_t num_outstanding_req;
+	struct Scsi_Host *host;
+
+	wait_queue_head_t waiting_to_drain;
+
+	/*
+	 * Each unique Port/Path/Target represents 1 channel ie scsi
+	 * controller. In reality, the pathid, targetid is always 0
+	 * and the port is set by us
+	 */
+	unsigned int port_number;
+	unsigned char path_id;
+	unsigned char target_id;
+
+	/* Used for vsc/vsp channel reset process */
+	struct hv_storvsc_request init_request;
+	struct hv_storvsc_request reset_request;
+};
+
+struct stor_mem_pools {
+	struct kmem_cache *request_pool;
+	mempool_t *request_mempool;
+};
+
+struct hv_host_device {
+	struct hv_device *dev;
+	unsigned int port;
+	unsigned char path;
+	unsigned char target;
+};
+
+struct storvsc_cmd_request {
+	struct list_head entry;
+	struct scsi_cmnd *cmd;
+
+	unsigned int bounce_sgl_count;
+	struct scatterlist *bounce_sgl;
+
+	struct hv_storvsc_request request;
+};
+
+struct storvsc_scan_work {
+	struct work_struct work;
+	struct Scsi_Host *host;
+	uint lun;
+};
+
+static void storvsc_bus_scan(struct work_struct *work)
+{
+	struct storvsc_scan_work *wrk;
+	int id, order_id;
+
+	wrk = container_of(work, struct storvsc_scan_work, work);
+	for (id = 0; id < wrk->host->max_id; ++id) {
+		if (wrk->host->reverse_ordering)
+			order_id = wrk->host->max_id - id - 1;
+		else
+			order_id = id;
+
+		scsi_scan_target(&wrk->host->shost_gendev, 0,
+				order_id, SCAN_WILD_CARD, 1);
+	}
+	kfree(wrk);
+}
+
+static void storvsc_remove_lun(struct work_struct *work)
+{
+	struct storvsc_scan_work *wrk;
+	struct scsi_device *sdev;
+
+	wrk = container_of(work, struct storvsc_scan_work, work);
+	if (!scsi_host_get(wrk->host))
+		goto done;
+
+	sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
+
+	if (sdev) {
+		scsi_remove_device(sdev);
+		scsi_device_put(sdev);
+	}
+	scsi_host_put(wrk->host);
+
+done:
+	kfree(wrk);
+}
+
+static inline struct storvsc_device *get_out_stor_device(
+					struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+
+	stor_device = hv_get_drvdata(device);
+
+	if (stor_device && stor_device->destroy)
+		stor_device = NULL;
+
+	return stor_device;
+}
+
+
+static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
+{
+	dev->drain_notify = true;
+	wait_event(dev->waiting_to_drain,
+		   atomic_read(&dev->num_outstanding_req) == 0);
+	dev->drain_notify = false;
+}
+
+static inline struct storvsc_device *get_in_stor_device(
+					struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+
+	stor_device = hv_get_drvdata(device);
+
+	if (!stor_device)
+		goto get_in_err;
+
+	/*
+	 * If the device is being destroyed; allow incoming
+	 * traffic only to cleanup outstanding requests.
+	 */
+
+	if (stor_device->destroy  &&
+		(atomic_read(&stor_device->num_outstanding_req) == 0))
+		stor_device = NULL;
+
+get_in_err:
+	return stor_device;
+
+}
+
+static int storvsc_channel_init(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	struct hv_storvsc_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return -ENODEV;
+
+	request = &stor_device->init_request;
+	vstor_packet = &request->vstor_packet;
+
+	/*
+	 * Now, initiate the vsc/vsp initialization protocol on the open
+	 * channel
+	 */
+	memset(request, 0, sizeof(struct hv_storvsc_request));
+	init_completion(&request->wait_event);
+	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+	/* reuse the packet for version range supported */
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	vstor_packet->version.major_minor = VMSTOR_PROTOCOL_VERSION_CURRENT;
+	FILL_VMSTOR_REVISION(vstor_packet->version.revision);
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->storage_channel_properties.port_number =
+					stor_device->port_number;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+	stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
+	stor_device->target_id
+		= vstor_packet->storage_channel_properties.target_id;
+
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+cleanup:
+	return ret;
+}
+
+static void storvsc_on_io_completion(struct hv_device *device,
+				  struct vstor_packet *vstor_packet,
+				  struct hv_storvsc_request *request)
+{
+	struct storvsc_device *stor_device;
+	struct vstor_packet *stor_pkt;
+
+	stor_device = hv_get_drvdata(device);
+	stor_pkt = &request->vstor_packet;
+
+	/*
+	 * The current SCSI handling on the host side does
+	 * not correctly handle:
+	 * INQUIRY command with page code parameter set to 0x80
+	 * MODE_SENSE command with cmd[2] == 0x1c
+	 *
+	 * Setup srb and scsi status so this won't be fatal.
+	 * We do this so we can distinguish truly fatal failues
+	 * (srb status == 0x4) and off-line the device in that case.
+	 */
+
+	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
+		(stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
+		vstor_packet->vm_srb.scsi_status = 0;
+		vstor_packet->vm_srb.srb_status = 0x1;
+	}
+
+
+	/* Copy over the status...etc */
+	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
+	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
+	stor_pkt->vm_srb.sense_info_length =
+	vstor_packet->vm_srb.sense_info_length;
+
+	if (vstor_packet->vm_srb.scsi_status != 0 ||
+		vstor_packet->vm_srb.srb_status != 1){
+		dev_warn(&device->device,
+			 "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
+			 stor_pkt->vm_srb.cdb[0],
+			 vstor_packet->vm_srb.scsi_status,
+			 vstor_packet->vm_srb.srb_status);
+	}
+
+	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
+		/* CHECK_CONDITION */
+		if (vstor_packet->vm_srb.srb_status & 0x80) {
+			/* autosense data available */
+			dev_warn(&device->device,
+				 "stor pkt %p autosense data valid - len %d\n",
+				 request,
+				 vstor_packet->vm_srb.sense_info_length);
+
+			memcpy(request->sense_buffer,
+			       vstor_packet->vm_srb.sense_data,
+			       vstor_packet->vm_srb.sense_info_length);
+
+		}
+	}
+
+	stor_pkt->vm_srb.data_transfer_length =
+	vstor_packet->vm_srb.data_transfer_length;
+
+	request->on_io_completion(request);
+
+	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
+		stor_device->drain_notify)
+		wake_up(&stor_device->waiting_to_drain);
+
+
+}
+
+static void storvsc_on_receive(struct hv_device *device,
+			     struct vstor_packet *vstor_packet,
+			     struct hv_storvsc_request *request)
+{
+	struct storvsc_scan_work *work;
+	struct storvsc_device *stor_device;
+
+	switch (vstor_packet->operation) {
+	case VSTOR_OPERATION_COMPLETE_IO:
+		storvsc_on_io_completion(device, vstor_packet, request);
+		break;
+
+	case VSTOR_OPERATION_REMOVE_DEVICE:
+	case VSTOR_OPERATION_ENUMERATE_BUS:
+		stor_device = get_in_stor_device(device);
+		work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
+		if (!work)
+			return;
+
+		INIT_WORK(&work->work, storvsc_bus_scan);
+		work->host = stor_device->host;
+		schedule_work(&work->work);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static void storvsc_on_channel_callback(void *context)
+{
+	struct hv_device *device = (struct hv_device *)context;
+	struct storvsc_device *stor_device;
+	u32 bytes_recvd;
+	u64 request_id;
+	unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
+	struct hv_storvsc_request *request;
+	int ret;
+
+
+	stor_device = get_in_stor_device(device);
+	if (!stor_device)
+		return;
+
+	do {
+		ret = vmbus_recvpacket(device->channel, packet,
+				       ALIGN(sizeof(struct vstor_packet), 8),
+				       &bytes_recvd, &request_id);
+		if (ret == 0 && bytes_recvd > 0) {
+
+			request = (struct hv_storvsc_request *)
+					(unsigned long)request_id;
+
+			if ((request == &stor_device->init_request) ||
+			    (request == &stor_device->reset_request)) {
+
+				memcpy(&request->vstor_packet, packet,
+				       sizeof(struct vstor_packet));
+				complete(&request->wait_event);
+			} else {
+				storvsc_on_receive(device,
+						(struct vstor_packet *)packet,
+						request);
+			}
+		} else {
+			break;
+		}
+	} while (1);
+
+	return;
+}
+
+static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
+{
+	struct vmstorage_channel_properties props;
+	int ret;
+
+	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
+
+	/* Open the channel */
+	ret = vmbus_open(device->channel,
+			 ring_size,
+			 ring_size,
+			 (void *)&props,
+			 sizeof(struct vmstorage_channel_properties),
+			 storvsc_on_channel_callback, device);
+
+	if (ret != 0)
+		return ret;
+
+	ret = storvsc_channel_init(device);
+
+	return ret;
+}
+
+static int storvsc_dev_remove(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	unsigned long flags;
+
+	stor_device = hv_get_drvdata(device);
+
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	stor_device->destroy = true;
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/*
+	 * At this point, all outbound traffic should be disable. We
+	 * only allow inbound traffic (responses) to proceed so that
+	 * outstanding requests can be completed.
+	 */
+
+	storvsc_wait_to_drain(stor_device);
+
+	/*
+	 * Since we have already drained, we don't need to busy wait
+	 * as was done in final_release_stor_device()
+	 * Note that we cannot set the ext pointer to NULL until
+	 * we have drained - to drain the outgoing packets, we need to
+	 * allow incoming packets.
+	 */
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	hv_set_drvdata(device, NULL);
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/* Close the channel */
+	vmbus_close(device->channel);
+
+	kfree(stor_device);
+	return 0;
+}
+
+static int storvsc_do_io(struct hv_device *device,
+			      struct hv_storvsc_request *request)
+{
+	struct storvsc_device *stor_device;
+	struct vstor_packet *vstor_packet;
+	int ret = 0;
+
+	vstor_packet = &request->vstor_packet;
+	stor_device = get_out_stor_device(device);
+
+	if (!stor_device)
+		return -ENODEV;
+
+
+	request->device  = device;
+
+
+	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
+
+	vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
+
+
+	vstor_packet->vm_srb.sense_info_length = SENSE_BUFFER_SIZE;
+
+
+	vstor_packet->vm_srb.data_transfer_length =
+	request->data_buffer.len;
+
+	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
+
+	if (request->data_buffer.len) {
+		ret = vmbus_sendpacket_multipagebuffer(device->channel,
+				&request->data_buffer,
+				vstor_packet,
+				sizeof(struct vstor_packet),
+				(unsigned long)request);
+	} else {
+		ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	}
+
+	if (ret != 0)
+		return ret;
+
+	atomic_inc(&stor_device->num_outstanding_req);
+
+	return ret;
+}
+
+static void storvsc_get_ide_info(struct hv_device *dev, int *target, int *path)
+{
+	*target =
+		dev->dev_instance.b[5] << 8 | dev->dev_instance.b[4];
+
+	*path =
+		dev->dev_instance.b[3] << 24 |
+		dev->dev_instance.b[2] << 16 |
+		dev->dev_instance.b[1] << 8  | dev->dev_instance.b[0];
+}
+
+
+static int storvsc_device_alloc(struct scsi_device *sdevice)
+{
+	struct stor_mem_pools *memp;
+	int number = STORVSC_MIN_BUF_NR;
+
+	memp = kzalloc(sizeof(struct stor_mem_pools), GFP_KERNEL);
+	if (!memp)
+		return -ENOMEM;
+
+	memp->request_pool =
+		kmem_cache_create(dev_name(&sdevice->sdev_dev),
+				sizeof(struct storvsc_cmd_request), 0,
+				SLAB_HWCACHE_ALIGN, NULL);
+
+	if (!memp->request_pool)
+		goto err0;
+
+	memp->request_mempool = mempool_create(number, mempool_alloc_slab,
+						mempool_free_slab,
+						memp->request_pool);
+
+	if (!memp->request_mempool)
+		goto err1;
+
+	sdevice->hostdata = memp;
+
+	return 0;
+
+err1:
+	kmem_cache_destroy(memp->request_pool);
+
+err0:
+	kfree(memp);
+	return -ENOMEM;
+}
+
+static void storvsc_device_destroy(struct scsi_device *sdevice)
+{
+	struct stor_mem_pools *memp = sdevice->hostdata;
+
+	mempool_destroy(memp->request_mempool);
+	kmem_cache_destroy(memp->request_pool);
+	kfree(memp);
+	sdevice->hostdata = NULL;
+}
+
+static int storvsc_device_configure(struct scsi_device *sdevice)
+{
+	scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
+				STORVSC_MAX_IO_REQUESTS);
+
+	blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
+
+	blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
+
+	return 0;
+}
+
+static void destroy_bounce_buffer(struct scatterlist *sgl,
+				  unsigned int sg_count)
+{
+	int i;
+	struct page *page_buf;
+
+	for (i = 0; i < sg_count; i++) {
+		page_buf = sg_page((&sgl[i]));
+		if (page_buf != NULL)
+			__free_page(page_buf);
+	}
+
+	kfree(sgl);
+}
+
+static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
+{
+	int i;
+
+	/* No need to check */
+	if (sg_count < 2)
+		return -1;
+
+	/* We have at least 2 sg entries */
+	for (i = 0; i < sg_count; i++) {
+		if (i == 0) {
+			/* make sure 1st one does not have hole */
+			if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
+				return i;
+		} else if (i == sg_count - 1) {
+			/* make sure last one does not have hole */
+			if (sgl[i].offset != 0)
+				return i;
+		} else {
+			/* make sure no hole in the middle */
+			if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
+				return i;
+		}
+	}
+	return -1;
+}
+
+static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
+						unsigned int sg_count,
+						unsigned int len)
+{
+	int i;
+	int num_pages;
+	struct scatterlist *bounce_sgl;
+	struct page *page_buf;
+
+	num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
+
+	bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
+	if (!bounce_sgl)
+		return NULL;
+
+	for (i = 0; i < num_pages; i++) {
+		page_buf = alloc_page(GFP_ATOMIC);
+		if (!page_buf)
+			goto cleanup;
+		sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
+	}
+
+	return bounce_sgl;
+
+cleanup:
+	destroy_bounce_buffer(bounce_sgl, num_pages);
+	return NULL;
+}
+
+
+/* Assume the original sgl has enough room */
+static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
+					    struct scatterlist *bounce_sgl,
+					    unsigned int orig_sgl_count,
+					    unsigned int bounce_sgl_count)
+{
+	int i;
+	int j = 0;
+	unsigned long src, dest;
+	unsigned int srclen, destlen, copylen;
+	unsigned int total_copied = 0;
+	unsigned long bounce_addr = 0;
+	unsigned long dest_addr = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for (i = 0; i < orig_sgl_count; i++) {
+		dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
+					KM_IRQ0) + orig_sgl[i].offset;
+		dest = dest_addr;
+		destlen = orig_sgl[i].length;
+
+		if (bounce_addr == 0)
+			bounce_addr =
+			(unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
+							KM_IRQ0);
+
+		while (destlen) {
+			src = bounce_addr + bounce_sgl[j].offset;
+			srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
+
+			copylen = min(srclen, destlen);
+			memcpy((void *)dest, (void *)src, copylen);
+
+			total_copied += copylen;
+			bounce_sgl[j].offset += copylen;
+			destlen -= copylen;
+			dest += copylen;
+
+			if (bounce_sgl[j].offset == bounce_sgl[j].length) {
+				/* full */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+				j++;
+
+				/*
+				 * It is possible that the number of elements
+				 * in the bounce buffer may not be equal to
+				 * the number of elements in the original
+				 * scatter list. Handle this correctly.
+				 */
+
+				if (j == bounce_sgl_count) {
+					/*
+					 * We are done; cleanup and return.
+					 */
+					kunmap_atomic((void *)(dest_addr -
+							orig_sgl[i].offset),
+							KM_IRQ0);
+					local_irq_restore(flags);
+					return total_copied;
+				}
+
+				/* if we need to use another bounce buffer */
+				if (destlen || i != orig_sgl_count - 1)
+					bounce_addr =
+					(unsigned long)kmap_atomic(
+					sg_page((&bounce_sgl[j])), KM_IRQ0);
+			} else if (destlen == 0 && i == orig_sgl_count - 1) {
+				/* unmap the last bounce that is < PAGE_SIZE */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+			}
+		}
+
+		kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
+			      KM_IRQ0);
+	}
+
+	local_irq_restore(flags);
+
+	return total_copied;
+}
+
+
+/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
+static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
+					  struct scatterlist *bounce_sgl,
+					  unsigned int orig_sgl_count)
+{
+	int i;
+	int j = 0;
+	unsigned long src, dest;
+	unsigned int srclen, destlen, copylen;
+	unsigned int total_copied = 0;
+	unsigned long bounce_addr = 0;
+	unsigned long src_addr = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for (i = 0; i < orig_sgl_count; i++) {
+		src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
+				KM_IRQ0) + orig_sgl[i].offset;
+		src = src_addr;
+		srclen = orig_sgl[i].length;
+
+		if (bounce_addr == 0)
+			bounce_addr =
+			(unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
+						KM_IRQ0);
+
+		while (srclen) {
+			/* assume bounce offset always == 0 */
+			dest = bounce_addr + bounce_sgl[j].length;
+			destlen = PAGE_SIZE - bounce_sgl[j].length;
+
+			copylen = min(srclen, destlen);
+			memcpy((void *)dest, (void *)src, copylen);
+
+			total_copied += copylen;
+			bounce_sgl[j].length += copylen;
+			srclen -= copylen;
+			src += copylen;
+
+			if (bounce_sgl[j].length == PAGE_SIZE) {
+				/* full..move to next entry */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+				j++;
+
+				/* if we need to use another bounce buffer */
+				if (srclen || i != orig_sgl_count - 1)
+					bounce_addr =
+					(unsigned long)kmap_atomic(
+					sg_page((&bounce_sgl[j])), KM_IRQ0);
+
+			} else if (srclen == 0 && i == orig_sgl_count - 1) {
+				/* unmap the last bounce that is < PAGE_SIZE */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+			}
+		}
+
+		kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
+	}
+
+	local_irq_restore(flags);
+
+	return total_copied;
+}
+
+
+static int storvsc_remove(struct hv_device *dev)
+{
+	struct storvsc_device *stor_device = hv_get_drvdata(dev);
+	struct Scsi_Host *host = stor_device->host;
+
+	scsi_remove_host(host);
+
+	scsi_host_put(host);
+
+	storvsc_dev_remove(dev);
+
+	return 0;
+}
+
+
+static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
+			   sector_t capacity, int *info)
+{
+	sector_t nsect = capacity;
+	sector_t cylinders = nsect;
+	int heads, sectors_pt;
+
+	/*
+	 * We are making up these values; let us keep it simple.
+	 */
+	heads = 0xff;
+	sectors_pt = 0x3f;      /* Sectors per track */
+	sector_div(cylinders, heads * sectors_pt);
+	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
+		cylinders = 0xffff;
+
+	info[0] = heads;
+	info[1] = sectors_pt;
+	info[2] = (int)cylinders;
+
+	return 0;
+}
+
+static int storvsc_host_reset(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	struct hv_storvsc_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return FAILED;
+
+	request = &stor_device->reset_request;
+	vstor_packet = &request->vstor_packet;
+
+	init_completion(&request->wait_event);
+
+	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->vm_srb.path_id = stor_device->path_id;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)&stor_device->reset_request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		return FAILED;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0)
+		return TIMEOUT_ERROR;
+
+
+	/*
+	 * At this point, all outstanding requests in the adapter
+	 * should have been flushed out and return to us
+	 */
+
+	return SUCCESS;
+}
+
+
+/*
+ * storvsc_host_reset_handler - Reset the scsi HBA
+ */
+static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
+{
+	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
+	struct hv_device *dev = host_dev->dev;
+
+	return storvsc_host_reset(dev);
+}
+
+
+/*
+ * storvsc_command_completion - Command completion processing
+ */
+static void storvsc_command_completion(struct hv_storvsc_request *request)
+{
+	struct storvsc_cmd_request *cmd_request =
+		(struct storvsc_cmd_request *)request->context;
+	struct scsi_cmnd *scmnd = cmd_request->cmd;
+	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
+	void (*scsi_done_fn)(struct scsi_cmnd *);
+	struct scsi_sense_hdr sense_hdr;
+	struct vmscsi_request *vm_srb;
+	struct storvsc_scan_work *wrk;
+	struct stor_mem_pools *memp = scmnd->device->hostdata;
+
+	vm_srb = &request->vstor_packet.vm_srb;
+	if (cmd_request->bounce_sgl_count) {
+		if (vm_srb->data_in == READ_TYPE)
+			copy_from_bounce_buffer(scsi_sglist(scmnd),
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd),
+					cmd_request->bounce_sgl_count);
+		destroy_bounce_buffer(cmd_request->bounce_sgl,
+					cmd_request->bounce_sgl_count);
+	}
+
+	/*
+	 * If there is an error; offline the device since all
+	 * error recovery strategies would have already been
+	 * deployed on the host side.
+	 */
+	if (vm_srb->srb_status == 0x4)
+		scmnd->result = DID_TARGET_FAILURE << 16;
+	else
+		scmnd->result = vm_srb->scsi_status;
+
+	/*
+	 * If the LUN is invalid; remove the device.
+	 */
+	if (vm_srb->srb_status == 0x20) {
+		struct storvsc_device *stor_dev;
+		struct hv_device *dev = host_dev->dev;
+		struct Scsi_Host *host;
+
+		stor_dev = get_in_stor_device(dev);
+		host = stor_dev->host;
+
+		wrk = kmalloc(sizeof(struct storvsc_scan_work),
+				GFP_ATOMIC);
+		if (!wrk) {
+			scmnd->result = DID_TARGET_FAILURE << 16;
+		} else {
+			wrk->host = host;
+			wrk->lun = vm_srb->lun;
+			INIT_WORK(&wrk->work, storvsc_remove_lun);
+			schedule_work(&wrk->work);
+		}
+	}
+
+	if (scmnd->result) {
+		if (scsi_normalize_sense(scmnd->sense_buffer,
+				SCSI_SENSE_BUFFERSIZE, &sense_hdr))
+			scsi_print_sense_hdr("storvsc", &sense_hdr);
+	}
+
+	scsi_set_resid(scmnd,
+		request->data_buffer.len -
+		vm_srb->data_transfer_length);
+
+	scsi_done_fn = scmnd->scsi_done;
+
+	scmnd->host_scribble = NULL;
+	scmnd->scsi_done = NULL;
+
+	scsi_done_fn(scmnd);
+
+	mempool_free(cmd_request, memp->request_mempool);
+}
+
+static bool storvsc_check_scsi_cmd(struct scsi_cmnd *scmnd)
+{
+	bool allowed = true;
+	u8 scsi_op = scmnd->cmnd[0];
+
+	switch (scsi_op) {
+	/* smartd sends this command, which will offline the device */
+	case SET_WINDOW:
+		scmnd->result = ILLEGAL_REQUEST << 16;
+		allowed = false;
+		break;
+	default:
+		break;
+	}
+	return allowed;
+}
+
+/*
+ * storvsc_queuecommand - Initiate command processing
+ */
+static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
+{
+	int ret;
+	struct hv_host_device *host_dev = shost_priv(host);
+	struct hv_device *dev = host_dev->dev;
+	struct hv_storvsc_request *request;
+	struct storvsc_cmd_request *cmd_request;
+	unsigned int request_size = 0;
+	int i;
+	struct scatterlist *sgl;
+	unsigned int sg_count = 0;
+	struct vmscsi_request *vm_srb;
+	struct stor_mem_pools *memp = scmnd->device->hostdata;
+
+	if (storvsc_check_scsi_cmd(scmnd) == false) {
+		scmnd->scsi_done(scmnd);
+		return 0;
+	}
+
+	/* If retrying, no need to prep the cmd */
+	if (scmnd->host_scribble) {
+
+		cmd_request =
+			(struct storvsc_cmd_request *)scmnd->host_scribble;
+
+		goto retry_request;
+	}
+
+	request_size = sizeof(struct storvsc_cmd_request);
+
+	cmd_request = mempool_alloc(memp->request_mempool,
+				       GFP_ATOMIC);
+	if (!cmd_request)
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+
+	memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
+
+	/* Setup the cmd request */
+	cmd_request->bounce_sgl_count = 0;
+	cmd_request->bounce_sgl = NULL;
+	cmd_request->cmd = scmnd;
+
+	scmnd->host_scribble = (unsigned char *)cmd_request;
+
+	request = &cmd_request->request;
+	vm_srb = &request->vstor_packet.vm_srb;
+
+
+	/* Build the SRB */
+	switch (scmnd->sc_data_direction) {
+	case DMA_TO_DEVICE:
+		vm_srb->data_in = WRITE_TYPE;
+		break;
+	case DMA_FROM_DEVICE:
+		vm_srb->data_in = READ_TYPE;
+		break;
+	default:
+		vm_srb->data_in = UNKNOWN_TYPE;
+		break;
+	}
+
+	request->on_io_completion = storvsc_command_completion;
+	request->context = cmd_request;/* scmnd; */
+
+	vm_srb->port_number = host_dev->port;
+	vm_srb->path_id = scmnd->device->channel;
+	vm_srb->target_id = scmnd->device->id;
+	vm_srb->lun = scmnd->device->lun;
+
+	vm_srb->cdb_length = scmnd->cmd_len;
+
+	memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
+
+	request->sense_buffer = scmnd->sense_buffer;
+
+
+	request->data_buffer.len = scsi_bufflen(scmnd);
+	if (scsi_sg_count(scmnd)) {
+		sgl = (struct scatterlist *)scsi_sglist(scmnd);
+		sg_count = scsi_sg_count(scmnd);
+
+		/* check if we need to bounce the sgl */
+		if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
+			cmd_request->bounce_sgl =
+				create_bounce_buffer(sgl, scsi_sg_count(scmnd),
+						     scsi_bufflen(scmnd));
+			if (!cmd_request->bounce_sgl) {
+				scmnd->host_scribble = NULL;
+				mempool_free(cmd_request,
+						memp->request_mempool);
+
+				return SCSI_MLQUEUE_HOST_BUSY;
+			}
+
+			cmd_request->bounce_sgl_count =
+				ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
+					PAGE_SHIFT;
+
+			if (vm_srb->data_in == WRITE_TYPE)
+				copy_to_bounce_buffer(sgl,
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd));
+
+			sgl = cmd_request->bounce_sgl;
+			sg_count = cmd_request->bounce_sgl_count;
+		}
+
+		request->data_buffer.offset = sgl[0].offset;
+
+		for (i = 0; i < sg_count; i++)
+			request->data_buffer.pfn_array[i] =
+				page_to_pfn(sg_page((&sgl[i])));
+
+	} else if (scsi_sglist(scmnd)) {
+		request->data_buffer.offset =
+			virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
+		request->data_buffer.pfn_array[0] =
+			virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
+	}
+
+retry_request:
+	/* Invokes the vsc to start an IO */
+	ret = storvsc_do_io(dev, &cmd_request->request);
+
+	if (ret == -EAGAIN) {
+		/* no more space */
+
+		if (cmd_request->bounce_sgl_count)
+			destroy_bounce_buffer(cmd_request->bounce_sgl,
+					cmd_request->bounce_sgl_count);
+
+		mempool_free(cmd_request, memp->request_mempool);
+
+		scmnd->host_scribble = NULL;
+
+		ret = SCSI_MLQUEUE_DEVICE_BUSY;
+	}
+
+	return ret;
+}
+
+/* Scsi driver */
+static struct scsi_host_template scsi_driver = {
+	.module	=		THIS_MODULE,
+	.name =			"storvsc_host_t",
+	.bios_param =		storvsc_get_chs,
+	.queuecommand =		storvsc_queuecommand,
+	.eh_host_reset_handler =	storvsc_host_reset_handler,
+	.slave_alloc =		storvsc_device_alloc,
+	.slave_destroy =	storvsc_device_destroy,
+	.slave_configure =	storvsc_device_configure,
+	.cmd_per_lun =		1,
+	/* 64 max_queue * 1 target */
+	.can_queue =		STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
+	.this_id =		-1,
+	/* no use setting to 0 since ll_blk_rw reset it to 1 */
+	/* currently 32 */
+	.sg_tablesize =		MAX_MULTIPAGE_BUFFER_COUNT,
+	.use_clustering =	DISABLE_CLUSTERING,
+	/* Make sure we dont get a sg segment crosses a page boundary */
+	.dma_boundary =		PAGE_SIZE-1,
+};
+
+enum {
+	SCSI_GUID,
+	IDE_GUID,
+};
+
+static const struct hv_vmbus_device_id id_table[] = {
+	/* SCSI guid */
+	{ VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
+		       0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
+	  .driver_data = SCSI_GUID },
+	/* IDE guid */
+	{ VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
+		       0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
+	  .driver_data = IDE_GUID },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(vmbus, id_table);
+
+
+/*
+ * storvsc_probe - Add a new device for this driver
+ */
+
+static int storvsc_probe(struct hv_device *device,
+			const struct hv_vmbus_device_id *dev_id)
+{
+	int ret;
+	struct Scsi_Host *host;
+	struct hv_host_device *host_dev;
+	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
+	int path = 0;
+	int target = 0;
+	struct storvsc_device *stor_device;
+
+	host = scsi_host_alloc(&scsi_driver,
+			       sizeof(struct hv_host_device));
+	if (!host)
+		return -ENOMEM;
+
+	host_dev = shost_priv(host);
+	memset(host_dev, 0, sizeof(struct hv_host_device));
+
+	host_dev->port = host->host_no;
+	host_dev->dev = device;
+
+
+	stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
+	if (!stor_device) {
+		ret = -ENOMEM;
+		goto err_out0;
+	}
+
+	stor_device->destroy = false;
+	init_waitqueue_head(&stor_device->waiting_to_drain);
+	stor_device->device = device;
+	stor_device->host = host;
+	hv_set_drvdata(device, stor_device);
+
+	stor_device->port_number = host->host_no;
+	ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
+	if (ret)
+		goto err_out1;
+
+	if (dev_is_ide)
+		storvsc_get_ide_info(device, &target, &path);
+
+	host_dev->path = stor_device->path_id;
+	host_dev->target = stor_device->target_id;
+
+	/* max # of devices per target */
+	host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
+	/* max # of targets per channel */
+	host->max_id = STORVSC_MAX_TARGETS;
+	/* max # of channels */
+	host->max_channel = STORVSC_MAX_CHANNELS - 1;
+	/* max cmd length */
+	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
+
+	/* Register the HBA and start the scsi bus scan */
+	ret = scsi_add_host(host, &device->device);
+	if (ret != 0)
+		goto err_out2;
+
+	if (!dev_is_ide) {
+		scsi_scan_host(host);
+		return 0;
+	}
+	ret = scsi_add_device(host, 0, target, 0);
+	if (ret) {
+		scsi_remove_host(host);
+		goto err_out2;
+	}
+	return 0;
+
+err_out2:
+	/*
+	 * Once we have connected with the host, we would need to
+	 * to invoke storvsc_dev_remove() to rollback this state and
+	 * this call also frees up the stor_device; hence the jump around
+	 * err_out1 label.
+	 */
+	storvsc_dev_remove(device);
+	goto err_out0;
+
+err_out1:
+	kfree(stor_device);
+
+err_out0:
+	scsi_host_put(host);
+	return ret;
+}
+
+/* The one and only one */
+
+static struct hv_driver storvsc_drv = {
+	.name = KBUILD_MODNAME,
+	.id_table = id_table,
+	.probe = storvsc_probe,
+	.remove = storvsc_remove,
+};
+
+static int __init storvsc_drv_init(void)
+{
+	u32 max_outstanding_req_per_channel;
+
+	/*
+	 * Divide the ring buffer data size (which is 1 page less
+	 * than the ring buffer size since that page is reserved for
+	 * the ring buffer indices) by the max request size (which is
+	 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
+	 */
+	max_outstanding_req_per_channel =
+		((storvsc_ringbuffer_size - PAGE_SIZE) /
+		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
+		sizeof(struct vstor_packet) + sizeof(u64),
+		sizeof(u64)));
+
+	if (max_outstanding_req_per_channel <
+	    STORVSC_MAX_IO_REQUESTS)
+		return -EINVAL;
+
+	return vmbus_driver_register(&storvsc_drv);
+}
+
+static void __exit storvsc_drv_exit(void)
+{
+	vmbus_driver_unregister(&storvsc_drv);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION(HV_DRV_VERSION);
+MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
+module_init(storvsc_drv_init);
+module_exit(storvsc_drv_exit);
-- 
1.7.4.1

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

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> -----Original Message-----
> From: KY Srinivasan
> Sent: Thursday, November 17, 2011 11:53 PM
> To: 'James Bottomley'
> Cc: gregkh@suse.de; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; virtualization@lists.osdl.org; linux-
> scsi@vger.kernel.org; ohering@suse.com; hch@infradead.org
> Subject: RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> 
> 
> > -----Original Message-----
> > From: James Bottomley [mailto:James.Bottomley@HansenPartnership.com]
> > Sent: Thursday, November 17, 2011 1:27 PM
> > To: KY Srinivasan
> > Cc: gregkh@suse.de; linux-kernel@vger.kernel.org;
> > devel@linuxdriverproject.org; virtualization@lists.osdl.org; linux-
> > scsi@vger.kernel.org; ohering@suse.com; hch@infradead.org
> > Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of
> the
> > staging area
> >
> > On Tue, 2011-11-08 at 10:13 -0800, K. Y. Srinivasan wrote:
> > > The storage driver (storvsc_drv.c) handles all block storage devices
> > > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > > staging tree for a while and this patch moves it out of the staging area.
> > > As per Greg's recommendation, this patch makes no changes to the
> staging/hv
> > > directory. Once the driver moves out of staging, we will cleanup the
> > > staging/hv directory.
> > >
> > > This patch includes all the patches that I have sent against the staging/hv
> > > tree to address the comments I have gotten to date on this storage driver.
> >
> > First comment is that it would have been easier to see the individual
> > patches for comment before you committed them.
> 
> I am not sure if the patches have been committed yet. All patches were sent
> to various mailing lists and you were copied as well. In the future, I will include
> the scsi mailing list in the set of lists I include for the staging patches.

Greg has checked in these patches now.

> 
> >
> > The way you did mempool isn't entirely right: the problem is that to
> > prevent a memory to I/O deadlock we need to ensure forward progress on
> > the drain device.  Just having 64 commands available to the host doesn't
> > necessarily achieve this because LUN1 could consume them all and starve
> > LUN0 which is the drain device leading to the deadlock, so the mempool
> > really needs to be per device using slave_alloc.
> 

Presently, Linux on Hyper-V can only boot from IDE devices. While IDE devices are
handled via this stor driver, the way we handle them is a little different compared
to block devices configured as scsi devices:

For  IDE devices; we have a HBA per LUN. Given that for a long time the drain device will
be an IDE device, my current implementation does address the concern that you had raised 
with regards to deadlock avoidance. 

> 
> >
> > +static int storvsc_device_alloc(struct scsi_device *sdevice)
> > +{
> > +	/*
> > +	 * This enables luns to be located sparsely. Otherwise, we may not
> > +	 * discovered them.
> > +	 */
> > +	sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
> > +	return 0;
> > +}
> >
> > Looks bogus ... this should happen automatically for SCSI-3 devices ...
> > unless your hypervisor has some strange (and wrong) identification?  I
> > really think you want to use SCSI-3 because it will do report LUN
> > scanning, which consumes far fewer resources.
> 

Done.

> 
> >
> > I still think you need to disable clustering and junk the bvec merge
> > function.  Your object seems to be to accumulate in page size multiples
> > (and not aggregate over this) ... that's what clustering is designed to
> > do.

Done. James, I am going to send you (and the scsi mailing list) the patches addressing 
your comments. I will also send out a consolidated patch for getting the driver out of 
staging as well. I would like to thank you for your help in cleaning up this driver.

Regards,

K. Y
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RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

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> -----Original Message-----
> From: James Bottomley [mailto:James.Bottomley@HansenPartnership.com]
> Sent: Friday, November 18, 2011 12:01 PM
> To: KY Srinivasan
> Cc: gregkh@suse.de; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; virtualization@lists.osdl.org; linux-
> scsi@vger.kernel.org; ohering@suse.com; hch@infradead.org
> Subject: RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Fri, 2011-11-18 at 04:53 +0000, KY Srinivasan wrote:
> > > I still think you need to disable clustering and junk the bvec merge
> > > function.  Your object seems to be to accumulate in page size multiples
> > > (and not aggregate over this) ... that's what clustering is designed to
> > > do.
> >
> > As part of addressing your first round of comments, I experimented with your
> > suggestions and I could not get rid of the code that does the bounce buffer
> handling.
> > I could generate I/O patterns that would require bounce buffer handling with
> your
> > suggestions in place.
> 
> There are two separate things here.  One is the scatter gather list
> bounce buffer processing, which is a bit nasty, but if you want to use <
> 4kb block size filesystems, I suppose I have to accept that you need it
> (although since it's a global fault of the hypervisor, perhaps it should
> sit in the hypervisor interface layer, so that every SG based transport
> can use it).  The other is the biovec merge function addition.  The
> purpose of this function seems to be to ensure you get one SG entry for
> every page (if I read it right)?  In that case, you don't need any of
> this special casing.  The flag DISABLE_CLUSTERING achieves the same
> thing.

Thanks James. I will keep you posted on my progress on this issue.

Regards,

K. Y

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RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[James Bottomley]

On Fri, 2011-11-18 at 04:53 +0000, KY Srinivasan wrote:
> > I still think you need to disable clustering and junk the bvec merge
> > function.  Your object seems to be to accumulate in page size multiples
> > (and not aggregate over this) ... that's what clustering is designed to
> > do.
> 
> As part of addressing your first round of comments, I experimented with your
> suggestions and I could not get rid of the code that does the bounce buffer handling.
> I could generate I/O patterns that would require bounce buffer handling with your
> suggestions in place.

There are two separate things here.  One is the scatter gather list
bounce buffer processing, which is a bit nasty, but if you want to use <
4kb block size filesystems, I suppose I have to accept that you need it
(although since it's a global fault of the hypervisor, perhaps it should
sit in the hypervisor interface layer, so that every SG based transport
can use it).  The other is the biovec merge function addition.  The
purpose of this function seems to be to ensure you get one SG entry for
every page (if I read it right)?  In that case, you don't need any of
this special casing.  The flag DISABLE_CLUSTERING achieves the same
thing.

James

RE: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[KY Srinivasan]

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> -----Original Message-----
> From: James Bottomley [mailto:James.Bottomley@HansenPartnership.com]
> Sent: Thursday, November 17, 2011 1:27 PM
> To: KY Srinivasan
> Cc: gregkh@suse.de; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; virtualization@lists.osdl.org; linux-
> scsi@vger.kernel.org; ohering@suse.com; hch@infradead.org
> Subject: Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the
> staging area
> 
> On Tue, 2011-11-08 at 10:13 -0800, K. Y. Srinivasan wrote:
> > The storage driver (storvsc_drv.c) handles all block storage devices
> > assigned to Linux guests hosted on Hyper-V. This driver has been in the
> > staging tree for a while and this patch moves it out of the staging area.
> > As per Greg's recommendation, this patch makes no changes to the staging/hv
> > directory. Once the driver moves out of staging, we will cleanup the
> > staging/hv directory.
> >
> > This patch includes all the patches that I have sent against the staging/hv
> > tree to address the comments I have gotten to date on this storage driver.
> 
> First comment is that it would have been easier to see the individual
> patches for comment before you committed them.

I am not sure if the patches have been committed yet. All patches were sent
to various mailing lists and you were copied as well. In the future, I will include
the scsi mailing list in the set of lists I include for the staging patches. 
 
> 
> The way you did mempool isn't entirely right: the problem is that to
> prevent a memory to I/O deadlock we need to ensure forward progress on
> the drain device.  Just having 64 commands available to the host doesn't
> necessarily achieve this because LUN1 could consume them all and starve
> LUN0 which is the drain device leading to the deadlock, so the mempool
> really needs to be per device using slave_alloc.

I will do this per LUN.

> 
> +static int storvsc_device_alloc(struct scsi_device *sdevice)
> +{
> +	/*
> +	 * This enables luns to be located sparsely. Otherwise, we may not
> +	 * discovered them.
> +	 */
> +	sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
> +	return 0;
> +}
> 
> Looks bogus ... this should happen automatically for SCSI-3 devices ...
> unless your hypervisor has some strange (and wrong) identification?  I
> really think you want to use SCSI-3 because it will do report LUN
> scanning, which consumes far fewer resources.

I will see if I can clean this up.

> 
> I still think you need to disable clustering and junk the bvec merge
> function.  Your object seems to be to accumulate in page size multiples
> (and not aggregate over this) ... that's what clustering is designed to
> do.

As part of addressing your first round of comments, I experimented with your
suggestions and I could not get rid of the code that does the bounce buffer handling.
I could generate I/O patterns that would require bounce buffer handling with your
suggestions in place.

Regards,

K. Y  

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Re: [PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[James Bottomley]

On Tue, 2011-11-08 at 10:13 -0800, K. Y. Srinivasan wrote:
> The storage driver (storvsc_drv.c) handles all block storage devices
> assigned to Linux guests hosted on Hyper-V. This driver has been in the
> staging tree for a while and this patch moves it out of the staging area.
> As per Greg's recommendation, this patch makes no changes to the staging/hv
> directory. Once the driver moves out of staging, we will cleanup the
> staging/hv directory.
> 
> This patch includes all the patches that I have sent against the staging/hv
> tree to address the comments I have gotten to date on this storage driver.

First comment is that it would have been easier to see the individual
patches for comment before you committed them.

The way you did mempool isn't entirely right: the problem is that to
prevent a memory to I/O deadlock we need to ensure forward progress on
the drain device.  Just having 64 commands available to the host doesn't
necessarily achieve this because LUN1 could consume them all and starve
LUN0 which is the drain device leading to the deadlock, so the mempool
really needs to be per device using slave_alloc.

+static int storvsc_device_alloc(struct scsi_device *sdevice)
+{
+	/*
+	 * This enables luns to be located sparsely. Otherwise, we may not
+	 * discovered them.
+	 */
+	sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
+	return 0;
+}

Looks bogus ... this should happen automatically for SCSI-3 devices ...
unless your hypervisor has some strange (and wrong) identification?  I
really think you want to use SCSI-3 because it will do report LUN
scanning, which consumes far fewer resources.

I still think you need to disable clustering and junk the bvec merge
function.  Your object seems to be to accumulate in page size multiples
(and not aggregate over this) ... that's what clustering is designed to
do.

James

[PATCH 1/1] Staging: hv: storvsc: Move the storage driver out of the staging area

[K. Y. Srinivasan]

The storage driver (storvsc_drv.c) handles all block storage devices
assigned to Linux guests hosted on Hyper-V. This driver has been in the
staging tree for a while and this patch moves it out of the staging area.
As per Greg's recommendation, this patch makes no changes to the staging/hv
directory. Once the driver moves out of staging, we will cleanup the
staging/hv directory.

This patch includes all the patches that I have sent against the staging/hv
tree to address the comments I have gotten to date on this storage driver.


Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/scsi/Kconfig       |    8 +
 drivers/scsi/Makefile      |    3 +
 drivers/scsi/storvsc_drv.c | 1567 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1578 insertions(+), 0 deletions(-)
 create mode 100644 drivers/scsi/storvsc_drv.c

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index aa573c3..2f72565 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -676,6 +676,14 @@ config VMWARE_PVSCSI
 	  To compile this driver as a module, choose M here: the
 	  module will be called vmw_pvscsi.
 
+config HYPERV_STORAGE
+	tristate "Microsoft Hyper-V virtual storage driver"
+	depends on SCSI && HYPERV
+	default HYPERV
+	help
+	  Select this option to enable the Hyper-V virtual storage driver.
+
+
 config LIBFC
 	tristate "LibFC module"
 	select SCSI_FC_ATTRS
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 2b88749..e4c1a69 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -142,6 +142,7 @@ obj-$(CONFIG_SCSI_BNX2_ISCSI)	+= libiscsi.o bnx2i/
 obj-$(CONFIG_BE2ISCSI)		+= libiscsi.o be2iscsi/
 obj-$(CONFIG_SCSI_PMCRAID)	+= pmcraid.o
 obj-$(CONFIG_VMWARE_PVSCSI)	+= vmw_pvscsi.o
+obj-$(CONFIG_HYPERV_STORAGE)	+= hv_storvsc.o
 
 obj-$(CONFIG_ARM)		+= arm/
 
@@ -170,6 +171,8 @@ scsi_mod-$(CONFIG_SCSI_PROC_FS)	+= scsi_proc.o
 scsi_mod-y			+= scsi_trace.o
 scsi_mod-$(CONFIG_PM)		+= scsi_pm.o
 
+hv_storvsc-y			:= storvsc_drv.o
+
 scsi_tgt-y			+= scsi_tgt_lib.o scsi_tgt_if.o
 
 sd_mod-objs	:= sd.o
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
new file mode 100644
index 0000000..0245143
--- /dev/null
+++ b/drivers/scsi/storvsc_drv.c
@@ -0,0 +1,1567 @@
+/*
+ * Copyright (c) 2009, Microsoft Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Authors:
+ *   Haiyang Zhang <haiyangz@microsoft.com>
+ *   Hank Janssen  <hjanssen@microsoft.com>
+ *   K. Y. Srinivasan <kys@microsoft.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/hyperv.h>
+#include <linux/mempool.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_devinfo.h>
+#include <scsi/scsi_dbg.h>
+
+
+#define STORVSC_MIN_BUF_NR				64
+#define STORVSC_RING_BUFFER_SIZE			(20*PAGE_SIZE)
+static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
+
+module_param(storvsc_ringbuffer_size, int, S_IRUGO);
+MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
+
+/* to alert the user that structure sizes may be mismatched even though the */
+/* protocol versions match. */
+
+
+#define REVISION_STRING(REVISION_) #REVISION_
+#define FILL_VMSTOR_REVISION(RESULT_LVALUE_)				\
+	do {								\
+		char *revision_string					\
+			= REVISION_STRING($Rev : 6 $) + 6;		\
+		RESULT_LVALUE_ = 0;					\
+		while (*revision_string >= '0'				\
+			&& *revision_string <= '9') {			\
+			RESULT_LVALUE_ *= 10;				\
+			RESULT_LVALUE_ += *revision_string - '0';	\
+			revision_string++;				\
+		}							\
+	} while (0)
+
+/* Major/minor macros.  Minor version is in LSB, meaning that earlier flat */
+/* version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1). */
+#define VMSTOR_PROTOCOL_MAJOR(VERSION_)		(((VERSION_) >> 8) & 0xff)
+#define VMSTOR_PROTOCOL_MINOR(VERSION_)		(((VERSION_))      & 0xff)
+#define VMSTOR_PROTOCOL_VERSION(MAJOR_, MINOR_)	((((MAJOR_) & 0xff) << 8) | \
+						 (((MINOR_) & 0xff)))
+#define VMSTOR_INVALID_PROTOCOL_VERSION		(-1)
+
+/* Version history: */
+/* V1 Beta                    0.1 */
+/* V1 RC < 2008/1/31          1.0 */
+/* V1 RC > 2008/1/31          2.0 */
+#define VMSTOR_PROTOCOL_VERSION_CURRENT VMSTOR_PROTOCOL_VERSION(4, 2)
+
+
+
+
+/*  This will get replaced with the max transfer length that is possible on */
+/*  the host adapter. */
+/*  The max transfer length will be published when we offer a vmbus channel. */
+#define MAX_TRANSFER_LENGTH	0x40000
+#define DEFAULT_PACKET_SIZE (sizeof(struct vmdata_gpa_direct) +	\
+			sizeof(struct vstor_packet) +		\
+			sizesizeof(u64) * (MAX_TRANSFER_LENGTH / PAGE_SIZE)))
+
+
+/*  Packet structure describing virtual storage requests. */
+enum vstor_packet_operation {
+	VSTOR_OPERATION_COMPLETE_IO		= 1,
+	VSTOR_OPERATION_REMOVE_DEVICE		= 2,
+	VSTOR_OPERATION_EXECUTE_SRB		= 3,
+	VSTOR_OPERATION_RESET_LUN		= 4,
+	VSTOR_OPERATION_RESET_ADAPTER		= 5,
+	VSTOR_OPERATION_RESET_BUS		= 6,
+	VSTOR_OPERATION_BEGIN_INITIALIZATION	= 7,
+	VSTOR_OPERATION_END_INITIALIZATION	= 8,
+	VSTOR_OPERATION_QUERY_PROTOCOL_VERSION	= 9,
+	VSTOR_OPERATION_QUERY_PROPERTIES	= 10,
+	VSTOR_OPERATION_ENUMERATE_BUS		= 11,
+	VSTOR_OPERATION_MAXIMUM			= 11
+};
+
+/*
+ * Platform neutral description of a scsi request -
+ * this remains the same across the write regardless of 32/64 bit
+ * note: it's patterned off the SCSI_PASS_THROUGH structure
+ */
+#define CDB16GENERIC_LENGTH			0x10
+
+#ifndef SENSE_BUFFER_SIZE
+#define SENSE_BUFFER_SIZE			0x12
+#endif
+
+#define MAX_DATA_BUF_LEN_WITH_PADDING		0x14
+
+struct vmscsi_request {
+	unsigned short length;
+	unsigned char srb_status;
+	unsigned char scsi_status;
+
+	unsigned char port_number;
+	unsigned char path_id;
+	unsigned char target_id;
+	unsigned char lun;
+
+	unsigned char cdb_length;
+	unsigned char sense_info_length;
+	unsigned char data_in;
+	unsigned char reserved;
+
+	unsigned int data_transfer_length;
+
+	union {
+		unsigned char cdb[CDB16GENERIC_LENGTH];
+		unsigned char sense_data[SENSE_BUFFER_SIZE];
+		unsigned char reserved_array[MAX_DATA_BUF_LEN_WITH_PADDING];
+	};
+} __attribute((packed));
+
+
+/*
+ * This structure is sent during the intialization phase to get the different
+ * properties of the channel.
+ */
+struct vmstorage_channel_properties {
+	unsigned short protocol_version;
+	unsigned char path_id;
+	unsigned char target_id;
+
+	/* Note: port number is only really known on the client side */
+	unsigned int port_number;
+	unsigned int flags;
+	unsigned int max_transfer_bytes;
+
+	/*  This id is unique for each channel and will correspond with */
+	/*  vendor specific data in the inquirydata */
+	unsigned long long unique_id;
+} __packed;
+
+/*  This structure is sent during the storage protocol negotiations. */
+struct vmstorage_protocol_version {
+	/* Major (MSW) and minor (LSW) version numbers. */
+	unsigned short major_minor;
+
+	/*
+	 * Revision number is auto-incremented whenever this file is changed
+	 * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
+	 * definitely indicate incompatibility--but it does indicate mismatched
+	 * builds.
+	 */
+	unsigned short revision;
+} __packed;
+
+/* Channel Property Flags */
+#define STORAGE_CHANNEL_REMOVABLE_FLAG		0x1
+#define STORAGE_CHANNEL_EMULATED_IDE_FLAG	0x2
+
+struct vstor_packet {
+	/* Requested operation type */
+	enum vstor_packet_operation operation;
+
+	/*  Flags - see below for values */
+	unsigned int flags;
+
+	/* Status of the request returned from the server side. */
+	unsigned int status;
+
+	/* Data payload area */
+	union {
+		/*
+		 * Structure used to forward SCSI commands from the
+		 * client to the server.
+		 */
+		struct vmscsi_request vm_srb;
+
+		/* Structure used to query channel properties. */
+		struct vmstorage_channel_properties storage_channel_properties;
+
+		/* Used during version negotiations. */
+		struct vmstorage_protocol_version version;
+	};
+} __packed;
+
+/* Packet flags */
+/*
+ * This flag indicates that the server should send back a completion for this
+ * packet.
+ */
+#define REQUEST_COMPLETION_FLAG	0x1
+
+/*  This is the set of flags that the vsc can set in any packets it sends */
+#define VSC_LEGAL_FLAGS		(REQUEST_COMPLETION_FLAG)
+
+
+/* Defines */
+
+#define STORVSC_MAX_IO_REQUESTS				128
+
+/*
+ * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
+ * reality, the path/target is not used (ie always set to 0) so our
+ * scsi host adapter essentially has 1 bus with 1 target that contains
+ * up to 256 luns.
+ */
+#define STORVSC_MAX_LUNS_PER_TARGET			64
+#define STORVSC_MAX_TARGETS				1
+#define STORVSC_MAX_CHANNELS				1
+#define STORVSC_MAX_CMD_LEN				16
+
+/* Matches Windows-end */
+enum storvsc_request_type {
+	WRITE_TYPE,
+	READ_TYPE,
+	UNKNOWN_TYPE,
+};
+
+
+struct hv_storvsc_request {
+	struct hv_device *device;
+
+	/* Synchronize the request/response if needed */
+	struct completion wait_event;
+
+	unsigned char *sense_buffer;
+	void *context;
+	void (*on_io_completion)(struct hv_storvsc_request *request);
+	struct hv_multipage_buffer data_buffer;
+
+	struct vstor_packet vstor_packet;
+};
+
+
+/* A storvsc device is a device object that contains a vmbus channel */
+struct storvsc_device {
+	struct hv_device *device;
+
+	bool	 destroy;
+	bool	 drain_notify;
+	atomic_t num_outstanding_req;
+	struct Scsi_Host *host;
+
+	wait_queue_head_t waiting_to_drain;
+
+	/*
+	 * Each unique Port/Path/Target represents 1 channel ie scsi
+	 * controller. In reality, the pathid, targetid is always 0
+	 * and the port is set by us
+	 */
+	unsigned int port_number;
+	unsigned char path_id;
+	unsigned char target_id;
+
+	/* Used for vsc/vsp channel reset process */
+	struct hv_storvsc_request init_request;
+	struct hv_storvsc_request reset_request;
+};
+
+struct hv_host_device {
+	struct hv_device *dev;
+	struct kmem_cache *request_pool;
+	mempool_t *request_mempool;
+	unsigned int port;
+	unsigned char path;
+	unsigned char target;
+};
+
+struct storvsc_cmd_request {
+	struct list_head entry;
+	struct scsi_cmnd *cmd;
+
+	unsigned int bounce_sgl_count;
+	struct scatterlist *bounce_sgl;
+
+	struct hv_storvsc_request request;
+};
+
+struct storvsc_scan_work {
+	struct work_struct work;
+	struct Scsi_Host *host;
+	uint lun;
+};
+
+static void storvsc_bus_scan(struct work_struct *work)
+{
+	struct storvsc_scan_work *wrk;
+	int id, order_id;
+
+	wrk = container_of(work, struct storvsc_scan_work, work);
+	for (id = 0; id < wrk->host->max_id; ++id) {
+		if (wrk->host->reverse_ordering)
+			order_id = wrk->host->max_id - id - 1;
+		else
+			order_id = id;
+
+		scsi_scan_target(&wrk->host->shost_gendev, 0,
+				order_id, SCAN_WILD_CARD, 1);
+	}
+	kfree(wrk);
+}
+
+static void storvsc_remove_lun(struct work_struct *work)
+{
+	struct storvsc_scan_work *wrk;
+	struct scsi_device *sdev;
+
+	wrk = container_of(work, struct storvsc_scan_work, work);
+	if (!scsi_host_get(wrk->host))
+		goto done;
+
+	sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
+
+	if (sdev) {
+		scsi_remove_device(sdev);
+		scsi_device_put(sdev);
+	}
+	scsi_host_put(wrk->host);
+
+done:
+	kfree(wrk);
+}
+
+static inline struct storvsc_device *get_out_stor_device(
+					struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+
+	stor_device = hv_get_drvdata(device);
+
+	if (stor_device && stor_device->destroy)
+		stor_device = NULL;
+
+	return stor_device;
+}
+
+
+static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
+{
+	dev->drain_notify = true;
+	wait_event(dev->waiting_to_drain,
+		   atomic_read(&dev->num_outstanding_req) == 0);
+	dev->drain_notify = false;
+}
+
+static inline struct storvsc_device *get_in_stor_device(
+					struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+
+	stor_device = hv_get_drvdata(device);
+
+	if (!stor_device)
+		goto get_in_err;
+
+	/*
+	 * If the device is being destroyed; allow incoming
+	 * traffic only to cleanup outstanding requests.
+	 */
+
+	if (stor_device->destroy  &&
+		(atomic_read(&stor_device->num_outstanding_req) == 0))
+		stor_device = NULL;
+
+get_in_err:
+	return stor_device;
+
+}
+
+static int storvsc_channel_init(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	struct hv_storvsc_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return -ENODEV;
+
+	request = &stor_device->init_request;
+	vstor_packet = &request->vstor_packet;
+
+	/*
+	 * Now, initiate the vsc/vsp initialization protocol on the open
+	 * channel
+	 */
+	memset(request, 0, sizeof(struct hv_storvsc_request));
+	init_completion(&request->wait_event);
+	vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+	/* reuse the packet for version range supported */
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	vstor_packet->version.major_minor = VMSTOR_PROTOCOL_VERSION_CURRENT;
+	FILL_VMSTOR_REVISION(vstor_packet->version.revision);
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->storage_channel_properties.port_number =
+					stor_device->port_number;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+	stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
+	stor_device->target_id
+		= vstor_packet->storage_channel_properties.target_id;
+
+	memset(vstor_packet, 0, sizeof(struct vstor_packet));
+	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		goto cleanup;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0) {
+		ret = -ETIMEDOUT;
+		goto cleanup;
+	}
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		goto cleanup;
+
+
+cleanup:
+	return ret;
+}
+
+static void storvsc_on_io_completion(struct hv_device *device,
+				  struct vstor_packet *vstor_packet,
+				  struct hv_storvsc_request *request)
+{
+	struct storvsc_device *stor_device;
+	struct vstor_packet *stor_pkt;
+
+	stor_device = hv_get_drvdata(device);
+	stor_pkt = &request->vstor_packet;
+
+	/*
+	 * The current SCSI handling on the host side does
+	 * not correctly handle:
+	 * INQUIRY command with page code parameter set to 0x80
+	 * MODE_SENSE command with cmd[2] == 0x1c
+	 *
+	 * Setup srb and scsi status so this won't be fatal.
+	 * We do this so we can distinguish truly fatal failues
+	 * (srb status == 0x4) and off-line the device in that case.
+	 */
+
+	if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
+		(stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
+		vstor_packet->vm_srb.scsi_status = 0;
+		vstor_packet->vm_srb.srb_status = 0x1;
+	}
+
+
+	/* Copy over the status...etc */
+	stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
+	stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
+	stor_pkt->vm_srb.sense_info_length =
+	vstor_packet->vm_srb.sense_info_length;
+
+	if (vstor_packet->vm_srb.scsi_status != 0 ||
+		vstor_packet->vm_srb.srb_status != 1){
+		dev_warn(&device->device,
+			 "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
+			 stor_pkt->vm_srb.cdb[0],
+			 vstor_packet->vm_srb.scsi_status,
+			 vstor_packet->vm_srb.srb_status);
+	}
+
+	if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
+		/* CHECK_CONDITION */
+		if (vstor_packet->vm_srb.srb_status & 0x80) {
+			/* autosense data available */
+			dev_warn(&device->device,
+				 "stor pkt %p autosense data valid - len %d\n",
+				 request,
+				 vstor_packet->vm_srb.sense_info_length);
+
+			memcpy(request->sense_buffer,
+			       vstor_packet->vm_srb.sense_data,
+			       vstor_packet->vm_srb.sense_info_length);
+
+		}
+	}
+
+	stor_pkt->vm_srb.data_transfer_length =
+	vstor_packet->vm_srb.data_transfer_length;
+
+	request->on_io_completion(request);
+
+	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
+		stor_device->drain_notify)
+		wake_up(&stor_device->waiting_to_drain);
+
+
+}
+
+static void storvsc_on_receive(struct hv_device *device,
+			     struct vstor_packet *vstor_packet,
+			     struct hv_storvsc_request *request)
+{
+	struct storvsc_scan_work *work;
+	struct storvsc_device *stor_device;
+
+	switch (vstor_packet->operation) {
+	case VSTOR_OPERATION_COMPLETE_IO:
+		storvsc_on_io_completion(device, vstor_packet, request);
+		break;
+
+	case VSTOR_OPERATION_REMOVE_DEVICE:
+	case VSTOR_OPERATION_ENUMERATE_BUS:
+		stor_device = get_in_stor_device(device);
+		work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
+		if (!work)
+			return;
+
+		INIT_WORK(&work->work, storvsc_bus_scan);
+		work->host = stor_device->host;
+		schedule_work(&work->work);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static void storvsc_on_channel_callback(void *context)
+{
+	struct hv_device *device = (struct hv_device *)context;
+	struct storvsc_device *stor_device;
+	u32 bytes_recvd;
+	u64 request_id;
+	unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
+	struct hv_storvsc_request *request;
+	int ret;
+
+
+	stor_device = get_in_stor_device(device);
+	if (!stor_device)
+		return;
+
+	do {
+		ret = vmbus_recvpacket(device->channel, packet,
+				       ALIGN(sizeof(struct vstor_packet), 8),
+				       &bytes_recvd, &request_id);
+		if (ret == 0 && bytes_recvd > 0) {
+
+			request = (struct hv_storvsc_request *)
+					(unsigned long)request_id;
+
+			if ((request == &stor_device->init_request) ||
+			    (request == &stor_device->reset_request)) {
+
+				memcpy(&request->vstor_packet, packet,
+				       sizeof(struct vstor_packet));
+				complete(&request->wait_event);
+			} else {
+				storvsc_on_receive(device,
+						(struct vstor_packet *)packet,
+						request);
+			}
+		} else {
+			break;
+		}
+	} while (1);
+
+	return;
+}
+
+static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
+{
+	struct vmstorage_channel_properties props;
+	int ret;
+
+	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
+
+	/* Open the channel */
+	ret = vmbus_open(device->channel,
+			 ring_size,
+			 ring_size,
+			 (void *)&props,
+			 sizeof(struct vmstorage_channel_properties),
+			 storvsc_on_channel_callback, device);
+
+	if (ret != 0)
+		return ret;
+
+	ret = storvsc_channel_init(device);
+
+	return ret;
+}
+
+static int storvsc_dev_remove(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	unsigned long flags;
+
+	stor_device = hv_get_drvdata(device);
+
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	stor_device->destroy = true;
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/*
+	 * At this point, all outbound traffic should be disable. We
+	 * only allow inbound traffic (responses) to proceed so that
+	 * outstanding requests can be completed.
+	 */
+
+	storvsc_wait_to_drain(stor_device);
+
+	/*
+	 * Since we have already drained, we don't need to busy wait
+	 * as was done in final_release_stor_device()
+	 * Note that we cannot set the ext pointer to NULL until
+	 * we have drained - to drain the outgoing packets, we need to
+	 * allow incoming packets.
+	 */
+	spin_lock_irqsave(&device->channel->inbound_lock, flags);
+	hv_set_drvdata(device, NULL);
+	spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
+
+	/* Close the channel */
+	vmbus_close(device->channel);
+
+	kfree(stor_device);
+	return 0;
+}
+
+static int storvsc_do_io(struct hv_device *device,
+			      struct hv_storvsc_request *request)
+{
+	struct storvsc_device *stor_device;
+	struct vstor_packet *vstor_packet;
+	int ret = 0;
+
+	vstor_packet = &request->vstor_packet;
+	stor_device = get_out_stor_device(device);
+
+	if (!stor_device)
+		return -ENODEV;
+
+
+	request->device  = device;
+
+
+	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
+
+	vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
+
+
+	vstor_packet->vm_srb.sense_info_length = SENSE_BUFFER_SIZE;
+
+
+	vstor_packet->vm_srb.data_transfer_length =
+	request->data_buffer.len;
+
+	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
+
+	if (request->data_buffer.len) {
+		ret = vmbus_sendpacket_multipagebuffer(device->channel,
+				&request->data_buffer,
+				vstor_packet,
+				sizeof(struct vstor_packet),
+				(unsigned long)request);
+	} else {
+		ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	}
+
+	if (ret != 0)
+		return ret;
+
+	atomic_inc(&stor_device->num_outstanding_req);
+
+	return ret;
+}
+
+static void storvsc_get_ide_info(struct hv_device *dev, int *target, int *path)
+{
+	*target =
+		dev->dev_instance.b[5] << 8 | dev->dev_instance.b[4];
+
+	*path =
+		dev->dev_instance.b[3] << 24 |
+		dev->dev_instance.b[2] << 16 |
+		dev->dev_instance.b[1] << 8  | dev->dev_instance.b[0];
+}
+
+
+static int storvsc_device_alloc(struct scsi_device *sdevice)
+{
+	/*
+	 * This enables luns to be located sparsely. Otherwise, we may not
+	 * discovered them.
+	 */
+	sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
+	return 0;
+}
+
+static int storvsc_merge_bvec(struct request_queue *q,
+			      struct bvec_merge_data *bmd, struct bio_vec *bvec)
+{
+	/* checking done by caller. */
+	return bvec->bv_len;
+}
+
+static int storvsc_device_configure(struct scsi_device *sdevice)
+{
+	scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
+				STORVSC_MAX_IO_REQUESTS);
+
+	blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
+
+	blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
+
+	blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
+
+	return 0;
+}
+
+static void destroy_bounce_buffer(struct scatterlist *sgl,
+				  unsigned int sg_count)
+{
+	int i;
+	struct page *page_buf;
+
+	for (i = 0; i < sg_count; i++) {
+		page_buf = sg_page((&sgl[i]));
+		if (page_buf != NULL)
+			__free_page(page_buf);
+	}
+
+	kfree(sgl);
+}
+
+static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
+{
+	int i;
+
+	/* No need to check */
+	if (sg_count < 2)
+		return -1;
+
+	/* We have at least 2 sg entries */
+	for (i = 0; i < sg_count; i++) {
+		if (i == 0) {
+			/* make sure 1st one does not have hole */
+			if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
+				return i;
+		} else if (i == sg_count - 1) {
+			/* make sure last one does not have hole */
+			if (sgl[i].offset != 0)
+				return i;
+		} else {
+			/* make sure no hole in the middle */
+			if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
+				return i;
+		}
+	}
+	return -1;
+}
+
+static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
+						unsigned int sg_count,
+						unsigned int len)
+{
+	int i;
+	int num_pages;
+	struct scatterlist *bounce_sgl;
+	struct page *page_buf;
+
+	num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
+
+	bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
+	if (!bounce_sgl)
+		return NULL;
+
+	for (i = 0; i < num_pages; i++) {
+		page_buf = alloc_page(GFP_ATOMIC);
+		if (!page_buf)
+			goto cleanup;
+		sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
+	}
+
+	return bounce_sgl;
+
+cleanup:
+	destroy_bounce_buffer(bounce_sgl, num_pages);
+	return NULL;
+}
+
+
+/* Assume the original sgl has enough room */
+static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
+					    struct scatterlist *bounce_sgl,
+					    unsigned int orig_sgl_count)
+{
+	int i;
+	int j = 0;
+	unsigned long src, dest;
+	unsigned int srclen, destlen, copylen;
+	unsigned int total_copied = 0;
+	unsigned long bounce_addr = 0;
+	unsigned long dest_addr = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for (i = 0; i < orig_sgl_count; i++) {
+		dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
+					KM_IRQ0) + orig_sgl[i].offset;
+		dest = dest_addr;
+		destlen = orig_sgl[i].length;
+
+		if (bounce_addr == 0)
+			bounce_addr =
+			(unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
+							KM_IRQ0);
+
+		while (destlen) {
+			src = bounce_addr + bounce_sgl[j].offset;
+			srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
+
+			copylen = min(srclen, destlen);
+			memcpy((void *)dest, (void *)src, copylen);
+
+			total_copied += copylen;
+			bounce_sgl[j].offset += copylen;
+			destlen -= copylen;
+			dest += copylen;
+
+			if (bounce_sgl[j].offset == bounce_sgl[j].length) {
+				/* full */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+				j++;
+
+				/* if we need to use another bounce buffer */
+				if (destlen || i != orig_sgl_count - 1)
+					bounce_addr =
+					(unsigned long)kmap_atomic(
+					sg_page((&bounce_sgl[j])), KM_IRQ0);
+			} else if (destlen == 0 && i == orig_sgl_count - 1) {
+				/* unmap the last bounce that is < PAGE_SIZE */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+			}
+		}
+
+		kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
+			      KM_IRQ0);
+	}
+
+	local_irq_restore(flags);
+
+	return total_copied;
+}
+
+
+/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
+static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
+					  struct scatterlist *bounce_sgl,
+					  unsigned int orig_sgl_count)
+{
+	int i;
+	int j = 0;
+	unsigned long src, dest;
+	unsigned int srclen, destlen, copylen;
+	unsigned int total_copied = 0;
+	unsigned long bounce_addr = 0;
+	unsigned long src_addr = 0;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for (i = 0; i < orig_sgl_count; i++) {
+		src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
+				KM_IRQ0) + orig_sgl[i].offset;
+		src = src_addr;
+		srclen = orig_sgl[i].length;
+
+		if (bounce_addr == 0)
+			bounce_addr =
+			(unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
+						KM_IRQ0);
+
+		while (srclen) {
+			/* assume bounce offset always == 0 */
+			dest = bounce_addr + bounce_sgl[j].length;
+			destlen = PAGE_SIZE - bounce_sgl[j].length;
+
+			copylen = min(srclen, destlen);
+			memcpy((void *)dest, (void *)src, copylen);
+
+			total_copied += copylen;
+			bounce_sgl[j].length += copylen;
+			srclen -= copylen;
+			src += copylen;
+
+			if (bounce_sgl[j].length == PAGE_SIZE) {
+				/* full..move to next entry */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+				j++;
+
+				/* if we need to use another bounce buffer */
+				if (srclen || i != orig_sgl_count - 1)
+					bounce_addr =
+					(unsigned long)kmap_atomic(
+					sg_page((&bounce_sgl[j])), KM_IRQ0);
+
+			} else if (srclen == 0 && i == orig_sgl_count - 1) {
+				/* unmap the last bounce that is < PAGE_SIZE */
+				kunmap_atomic((void *)bounce_addr, KM_IRQ0);
+			}
+		}
+
+		kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
+	}
+
+	local_irq_restore(flags);
+
+	return total_copied;
+}
+
+
+static int storvsc_remove(struct hv_device *dev)
+{
+	struct storvsc_device *stor_device = hv_get_drvdata(dev);
+	struct Scsi_Host *host = stor_device->host;
+	struct hv_host_device *host_dev = shost_priv(host);
+
+	scsi_remove_host(host);
+
+	scsi_host_put(host);
+
+	storvsc_dev_remove(dev);
+	if (host_dev->request_pool) {
+		mempool_destroy(host_dev->request_mempool);
+		kmem_cache_destroy(host_dev->request_pool);
+		host_dev->request_pool = NULL;
+		host_dev->request_mempool = NULL;
+	}
+	return 0;
+}
+
+
+static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
+			   sector_t capacity, int *info)
+{
+	sector_t nsect = capacity;
+	sector_t cylinders = nsect;
+	int heads, sectors_pt;
+
+	/*
+	 * We are making up these values; let us keep it simple.
+	 */
+	heads = 0xff;
+	sectors_pt = 0x3f;      /* Sectors per track */
+	sector_div(cylinders, heads * sectors_pt);
+	if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
+		cylinders = 0xffff;
+
+	info[0] = heads;
+	info[1] = sectors_pt;
+	info[2] = (int)cylinders;
+
+	return 0;
+}
+
+static int storvsc_host_reset(struct hv_device *device)
+{
+	struct storvsc_device *stor_device;
+	struct hv_storvsc_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return FAILED;
+
+	request = &stor_device->reset_request;
+	vstor_packet = &request->vstor_packet;
+
+	init_completion(&request->wait_event);
+
+	vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->vm_srb.path_id = stor_device->path_id;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       sizeof(struct vstor_packet),
+			       (unsigned long)&stor_device->reset_request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0)
+		return FAILED;
+
+	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+	if (t == 0)
+		return TIMEOUT_ERROR;
+
+
+	/*
+	 * At this point, all outstanding requests in the adapter
+	 * should have been flushed out and return to us
+	 */
+
+	return SUCCESS;
+}
+
+
+/*
+ * storvsc_host_reset_handler - Reset the scsi HBA
+ */
+static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
+{
+	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
+	struct hv_device *dev = host_dev->dev;
+
+	return storvsc_host_reset(dev);
+}
+
+
+/*
+ * storvsc_command_completion - Command completion processing
+ */
+static void storvsc_command_completion(struct hv_storvsc_request *request)
+{
+	struct storvsc_cmd_request *cmd_request =
+		(struct storvsc_cmd_request *)request->context;
+	struct scsi_cmnd *scmnd = cmd_request->cmd;
+	struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
+	void (*scsi_done_fn)(struct scsi_cmnd *);
+	struct scsi_sense_hdr sense_hdr;
+	struct vmscsi_request *vm_srb;
+	struct storvsc_scan_work *wrk;
+
+	vm_srb = &request->vstor_packet.vm_srb;
+	if (cmd_request->bounce_sgl_count) {
+		if (vm_srb->data_in == READ_TYPE) {
+			copy_from_bounce_buffer(scsi_sglist(scmnd),
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd));
+			destroy_bounce_buffer(cmd_request->bounce_sgl,
+					cmd_request->bounce_sgl_count);
+		}
+	}
+
+	/*
+	 * If there is an error; offline the device since all
+	 * error recovery strategies would have already been
+	 * deployed on the host side.
+	 */
+	if (vm_srb->srb_status == 0x4)
+		scmnd->result = DID_TARGET_FAILURE << 16;
+	else
+		scmnd->result = vm_srb->scsi_status;
+
+	/*
+	 * If the LUN is invalid; remove the device.
+	 */
+	if (vm_srb->srb_status == 0x20) {
+		struct storvsc_device *stor_dev;
+		struct hv_device *dev = host_dev->dev;
+		struct Scsi_Host *host;
+
+		stor_dev = get_in_stor_device(dev);
+		host = stor_dev->host;
+
+		wrk = kmalloc(sizeof(struct storvsc_scan_work),
+				GFP_ATOMIC);
+		if (!wrk) {
+			scmnd->result = DID_TARGET_FAILURE << 16;
+		} else {
+			wrk->host = host;
+			wrk->lun = vm_srb->lun;
+			INIT_WORK(&wrk->work, storvsc_remove_lun);
+			schedule_work(&wrk->work);
+		}
+	}
+
+	if (scmnd->result) {
+		if (scsi_normalize_sense(scmnd->sense_buffer,
+				SCSI_SENSE_BUFFERSIZE, &sense_hdr))
+			scsi_print_sense_hdr("storvsc", &sense_hdr);
+	}
+
+	scsi_set_resid(scmnd,
+		request->data_buffer.len -
+		vm_srb->data_transfer_length);
+
+	scsi_done_fn = scmnd->scsi_done;
+
+	scmnd->host_scribble = NULL;
+	scmnd->scsi_done = NULL;
+
+	scsi_done_fn(scmnd);
+
+	mempool_free(cmd_request, host_dev->request_mempool);
+}
+
+static bool storvsc_check_scsi_cmd(struct scsi_cmnd *scmnd)
+{
+	bool allowed = true;
+	u8 scsi_op = scmnd->cmnd[0];
+
+	switch (scsi_op) {
+	/* smartd sends this command, which will offline the device */
+	case SET_WINDOW:
+		scmnd->result = ILLEGAL_REQUEST << 16;
+		allowed = false;
+		break;
+	default:
+		break;
+	}
+	return allowed;
+}
+
+/*
+ * storvsc_queuecommand - Initiate command processing
+ */
+static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
+{
+	int ret;
+	struct hv_host_device *host_dev = shost_priv(host);
+	struct hv_device *dev = host_dev->dev;
+	struct hv_storvsc_request *request;
+	struct storvsc_cmd_request *cmd_request;
+	unsigned int request_size = 0;
+	int i;
+	struct scatterlist *sgl;
+	unsigned int sg_count = 0;
+	struct vmscsi_request *vm_srb;
+
+	if (storvsc_check_scsi_cmd(scmnd) == false) {
+		scmnd->scsi_done(scmnd);
+		return 0;
+	}
+
+	/* If retrying, no need to prep the cmd */
+	if (scmnd->host_scribble) {
+
+		cmd_request =
+			(struct storvsc_cmd_request *)scmnd->host_scribble;
+
+		goto retry_request;
+	}
+
+	request_size = sizeof(struct storvsc_cmd_request);
+
+	cmd_request = mempool_alloc(host_dev->request_mempool,
+				       GFP_ATOMIC);
+	if (!cmd_request)
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+
+	memset(cmd_request, 0, sizeof(struct storvsc_cmd_request));
+
+	/* Setup the cmd request */
+	cmd_request->bounce_sgl_count = 0;
+	cmd_request->bounce_sgl = NULL;
+	cmd_request->cmd = scmnd;
+
+	scmnd->host_scribble = (unsigned char *)cmd_request;
+
+	request = &cmd_request->request;
+	vm_srb = &request->vstor_packet.vm_srb;
+
+
+	/* Build the SRB */
+	switch (scmnd->sc_data_direction) {
+	case DMA_TO_DEVICE:
+		vm_srb->data_in = WRITE_TYPE;
+		break;
+	case DMA_FROM_DEVICE:
+		vm_srb->data_in = READ_TYPE;
+		break;
+	default:
+		vm_srb->data_in = UNKNOWN_TYPE;
+		break;
+	}
+
+	request->on_io_completion = storvsc_command_completion;
+	request->context = cmd_request;/* scmnd; */
+
+	vm_srb->port_number = host_dev->port;
+	vm_srb->path_id = scmnd->device->channel;
+	vm_srb->target_id = scmnd->device->id;
+	vm_srb->lun = scmnd->device->lun;
+
+	vm_srb->cdb_length = scmnd->cmd_len;
+
+	memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
+
+	request->sense_buffer = scmnd->sense_buffer;
+
+
+	request->data_buffer.len = scsi_bufflen(scmnd);
+	if (scsi_sg_count(scmnd)) {
+		sgl = (struct scatterlist *)scsi_sglist(scmnd);
+		sg_count = scsi_sg_count(scmnd);
+
+		/* check if we need to bounce the sgl */
+		if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
+			cmd_request->bounce_sgl =
+				create_bounce_buffer(sgl, scsi_sg_count(scmnd),
+						     scsi_bufflen(scmnd));
+			if (!cmd_request->bounce_sgl) {
+				scmnd->host_scribble = NULL;
+				mempool_free(cmd_request,
+						host_dev->request_mempool);
+
+				return SCSI_MLQUEUE_HOST_BUSY;
+			}
+
+			cmd_request->bounce_sgl_count =
+				ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
+					PAGE_SHIFT;
+
+			if (vm_srb->data_in == WRITE_TYPE)
+				copy_to_bounce_buffer(sgl,
+					cmd_request->bounce_sgl,
+					scsi_sg_count(scmnd));
+
+			sgl = cmd_request->bounce_sgl;
+			sg_count = cmd_request->bounce_sgl_count;
+		}
+
+		request->data_buffer.offset = sgl[0].offset;
+
+		for (i = 0; i < sg_count; i++)
+			request->data_buffer.pfn_array[i] =
+				page_to_pfn(sg_page((&sgl[i])));
+
+	} else if (scsi_sglist(scmnd)) {
+		request->data_buffer.offset =
+			virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
+		request->data_buffer.pfn_array[0] =
+			virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
+	}
+
+retry_request:
+	/* Invokes the vsc to start an IO */
+	ret = storvsc_do_io(dev, &cmd_request->request);
+
+	if (ret == -EAGAIN) {
+		/* no more space */
+
+		if (cmd_request->bounce_sgl_count)
+			destroy_bounce_buffer(cmd_request->bounce_sgl,
+					cmd_request->bounce_sgl_count);
+
+		mempool_free(cmd_request, host_dev->request_mempool);
+
+		scmnd->host_scribble = NULL;
+
+		ret = SCSI_MLQUEUE_DEVICE_BUSY;
+	}
+
+	return ret;
+}
+
+/* Scsi driver */
+static struct scsi_host_template scsi_driver = {
+	.module	=		THIS_MODULE,
+	.name =			"storvsc_host_t",
+	.bios_param =		storvsc_get_chs,
+	.queuecommand =		storvsc_queuecommand,
+	.eh_host_reset_handler =	storvsc_host_reset_handler,
+	.slave_alloc =		storvsc_device_alloc,
+	.slave_configure =	storvsc_device_configure,
+	.cmd_per_lun =		1,
+	/* 64 max_queue * 1 target */
+	.can_queue =		STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
+	.this_id =		-1,
+	/* no use setting to 0 since ll_blk_rw reset it to 1 */
+	/* currently 32 */
+	.sg_tablesize =		MAX_MULTIPAGE_BUFFER_COUNT,
+	/*
+	 * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
+	 * into 1 sg element. If set, we must limit the max_segment_size to
+	 * PAGE_SIZE, otherwise we may get 1 sg element that represents
+	 * multiple
+	 */
+	/* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
+	.use_clustering =	ENABLE_CLUSTERING,
+	/* Make sure we dont get a sg segment crosses a page boundary */
+	.dma_boundary =		PAGE_SIZE-1,
+};
+
+enum {
+	SCSI_GUID,
+	IDE_GUID,
+};
+
+static const struct hv_vmbus_device_id id_table[] = {
+	/* SCSI guid */
+	{ VMBUS_DEVICE(0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
+		       0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
+	  .driver_data = SCSI_GUID },
+	/* IDE guid */
+	{ VMBUS_DEVICE(0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
+		       0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
+	  .driver_data = IDE_GUID },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(vmbus, id_table);
+
+
+/*
+ * storvsc_probe - Add a new device for this driver
+ */
+
+static int storvsc_probe(struct hv_device *device,
+			const struct hv_vmbus_device_id *dev_id)
+{
+	int ret;
+	int number = STORVSC_MIN_BUF_NR;
+	struct Scsi_Host *host;
+	struct hv_host_device *host_dev;
+	bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
+	int path = 0;
+	int target = 0;
+	struct storvsc_device *stor_device;
+
+	host = scsi_host_alloc(&scsi_driver,
+			       sizeof(struct hv_host_device));
+	if (!host)
+		return -ENOMEM;
+
+	host_dev = shost_priv(host);
+	memset(host_dev, 0, sizeof(struct hv_host_device));
+
+	host_dev->port = host->host_no;
+	host_dev->dev = device;
+
+	host_dev->request_pool =
+				kmem_cache_create(dev_name(&device->device),
+					sizeof(struct storvsc_cmd_request), 0,
+					SLAB_HWCACHE_ALIGN, NULL);
+
+	if (!host_dev->request_pool) {
+		scsi_host_put(host);
+		return -ENOMEM;
+	}
+
+	host_dev->request_mempool = mempool_create(number, mempool_alloc_slab,
+						mempool_free_slab,
+						host_dev->request_pool);
+
+	if (!host_dev->request_mempool) {
+		ret = -ENOMEM;
+		goto err_out0;
+	}
+
+	stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
+	if (!stor_device) {
+		ret = -ENOMEM;
+		goto err_out1;
+	}
+
+	stor_device->destroy = false;
+	init_waitqueue_head(&stor_device->waiting_to_drain);
+	stor_device->device = device;
+	stor_device->host = host;
+	hv_set_drvdata(device, stor_device);
+
+	stor_device->port_number = host->host_no;
+	ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
+	if (ret)
+		goto err_out2;
+
+	if (dev_is_ide)
+		storvsc_get_ide_info(device, &target, &path);
+
+	host_dev->path = stor_device->path_id;
+	host_dev->target = stor_device->target_id;
+
+	/* max # of devices per target */
+	host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
+	/* max # of targets per channel */
+	host->max_id = STORVSC_MAX_TARGETS;
+	/* max # of channels */
+	host->max_channel = STORVSC_MAX_CHANNELS - 1;
+	/* max cmd length */
+	host->max_cmd_len = STORVSC_MAX_CMD_LEN;
+
+	/* Register the HBA and start the scsi bus scan */
+	ret = scsi_add_host(host, &device->device);
+	if (ret != 0)
+		goto err_out3;
+
+	if (!dev_is_ide) {
+		scsi_scan_host(host);
+		return 0;
+	}
+	ret = scsi_add_device(host, 0, target, 0);
+	if (ret) {
+		scsi_remove_host(host);
+		goto err_out3;
+	}
+	return 0;
+
+err_out3:
+	/*
+	 * Once we have connected with the host, we would need to
+	 * to invoke storvsc_dev_remove() to rollback this state and
+	 * this call also frees up the stor_device; hence the jump around
+	 * err_out2 label.
+	 */
+	storvsc_dev_remove(device);
+	goto err_out1;
+
+err_out2:
+	kfree(stor_device);
+
+err_out1:
+	mempool_destroy(host_dev->request_mempool);
+
+err_out0:
+	kmem_cache_destroy(host_dev->request_pool);
+	scsi_host_put(host);
+	return ret;
+}
+
+/* The one and only one */
+
+static struct hv_driver storvsc_drv = {
+	.name = KBUILD_MODNAME,
+	.id_table = id_table,
+	.probe = storvsc_probe,
+	.remove = storvsc_remove,
+};
+
+static int __init storvsc_drv_init(void)
+{
+	u32 max_outstanding_req_per_channel;
+
+	/*
+	 * Divide the ring buffer data size (which is 1 page less
+	 * than the ring buffer size since that page is reserved for
+	 * the ring buffer indices) by the max request size (which is
+	 * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
+	 */
+	max_outstanding_req_per_channel =
+		((storvsc_ringbuffer_size - PAGE_SIZE) /
+		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
+		sizeof(struct vstor_packet) + sizeof(u64),
+		sizeof(u64)));
+
+	if (max_outstanding_req_per_channel <
+	    STORVSC_MAX_IO_REQUESTS)
+		return -EINVAL;
+
+	return vmbus_driver_register(&storvsc_drv);
+}
+
+static void __exit storvsc_drv_exit(void)
+{
+	vmbus_driver_unregister(&storvsc_drv);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION(HV_DRV_VERSION);
+MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
+module_init(storvsc_drv_init);
+module_exit(storvsc_drv_exit);
-- 
1.7.4.1